Comments on: How To Connect Batteries In Series and Parallel

By: Ron sible

Ron sible — Wed, 18 Feb 2026 16:34:19 -0800

Thanks for the refresher course, well done! In a previous life, I worked with lots of battery's. That was a lot of years ago, rather not say where or how.

By: Ron sible

Ron sible — Wed, 18 Feb 2026 16:26:55 -0800

Thanks for the refresher course, well done!!!

By: Dennis Deman

Dennis Deman — Mon, 16 Feb 2026 16:05:23 -0800

How do I wire 3 12 volt batteries to make 24 volts?

By: Bill Watkins

Bill Watkins — Thu, 18 Dec 2025 21:31:58 -0800

Thanks, you did a very good job of explaining these different ways to employ the use of multiple batteries and the different arrangements for producing different results, this producing different results for different needs.

By: Mark Simko

Mark Simko — Sat, 22 Nov 2025 00:46:56 -0800

I need to hook up ( 2) 12 volt batteries for my snowplow. Do I need series or parallel?

By: Douglas seibel

Douglas seibel — Fri, 10 Oct 2025 00:02:29 -0700

I have 4 12v-75 ah batteries I want to make it 24v-150 ah do I put in series first then parallel or what would be the best way to increase the ah but only increase the v-24v

By: Jeff Smith

Jeff Smith — Thu, 18 Sep 2025 08:19:16 -0700

If I connect 2 24 volt 100ah batteries parallel will that increase it to 200ah

By: Dan W

Dan W — Wed, 17 Sep 2025 09:00:26 -0700

Solar series-parallel 4x2 6V batteries for 24 V. Are there special terminal post connectors/cables where 2 cables must connect to each end post where the array connects to the load- one to the rest of the battery array and the other to the load? Thanks in advance.

By: Jerry Pierson

Jerry Pierson — Mon, 15 Sep 2025 16:54:39 -0700

Can I wire 5 12v batteries in parallel? where would the feed start +-

By: Terry Carbary

Terry Carbary — Sat, 09 Aug 2025 09:18:39 -0700

I have an electric go cart 48v, 4 12.8 10Ah wired in series, ran for 15 minutes. One battery now reads zero voltage, other 3 are 13.3 volts. This is all new equipment. We enclosed batteries and controller in a metal box with lid. 70 degree day. Batteries got hot. Now ordering one new battery and try again. Please advise

By: Dave

Dave — Wed, 09 Jul 2025 14:17:06 -0700

I have 2x300 AH batteries x12.8 volts each to power my 2,000 watt pure sine inverter for my full time 5th wheel needs my inverter will accept 12 24 or 48 volts would it be better to hook my batteries up in series or parallel for my 110 volt needs tv fridge chargers thank you dave

By: Utibe Anthony Bassey

Utibe Anthony Bassey — Tue, 17 Jun 2025 02:32:10 -0700

This article is really educative, I like it.

By: Jerry

Jerry — Sun, 15 Jun 2025 05:53:30 -0700

Thank you

By: James linehan

James linehan — Wed, 15 Jan 2025 23:26:53 -0800

For installing a power stereo system in a vehicle would more voltage be required or more amp hours

By: Robert W

Robert W — Thu, 09 Jan 2025 09:31:35 -0800

Great read! I have 2 wind turbines that will charge 24v each. My question is with four 12v batteries can I create two 24v battery banks wired series-parallel to create a 48v output to inverter, and still use each turbine to charge the two 24v banks? (One 24v wind turbine connected to one 24v battery bank) Thank you in advance!

By: Donald W Akers

Donald W Akers — Tue, 07 Jan 2025 13:35:22 -0800

I'm wanting to do 4 sets 12 volts to 24 volt series, then paraelle to keep 800ah.

By: Mohammed Ibrahim Ibrahim

Mohammed Ibrahim Ibrahim — Sun, 08 Dec 2024 15:55:47 -0800

How to connect two batteries 220ah to 1.5kva 48v inverter

By: Dave L

Dave L — Fri, 01 Nov 2024 19:54:32 -0700

How would I add an additional 70Ah to the series parallel 24v battery bank you just described? Would I need 2 or 4 additional 35Ah batteries and how would I connect them to finish up with 24v 140Ah battery?

By: Bala Elisha

Bala Elisha — Sun, 11 Aug 2024 12:52:08 -0700

I'm convince with your perfect explanation.

By: AKV

AKV — Tue, 23 Jul 2024 23:49:59 -0700

We have connected 2x12V, 120AH batteries in parallel and it is charged by a 900VA inverter with PF of 0.7. Load is around 600W. What should be the ideal backup time for such an arrangement?

By: Terry Decker

Terry Decker — Mon, 15 Jul 2024 09:46:23 -0700

can I run 6 12 volt batteries in series with a 24 volt charge controller

By: John Cope

John Cope — Mon, 03 Jun 2024 03:23:26 -0700

very infomative

By: Greg Kristoff

Greg Kristoff — Mon, 08 Apr 2024 06:50:21 -0700

I have 2 x8v cart batteries and 2x6v deep cycles . Can they be hooked in series/parallel 8+6 =14 and charged with a 12 v charger

By: steven smith

steven smith — Thu, 28 Mar 2024 12:51:39 -0700

Problem i cant figure out!!! 4 12 volt agm wired in series and parallel when charging with victron 12/24 individual batteries read 15.5 12.5 15.5 18.00 all new batts all have same charge??????wiring matches schematic . one 15.5 has positive from alternator, the 18.00 has the negative

By: Joe Smith

Joe Smith — Thu, 29 Feb 2024 21:23:01 -0800

Have a battery back up system in a house I bought and replacing the batteries it had 8 6v 200ah SLA batteries, so 48v 200ah. What would be the best replacement batteries. The best I can find is 12v 130ah, 4 in series but then my wattege is cut 30%.

By: Joe Smith

Joe Smith — Thu, 29 Feb 2024 19:29:53 -0800

Hello I have a battery backup system on our new home. It has 8 6v 200ah batteries in series. Unfortunately those batteries are unavailable. I can access 12v 100ah or 12v 130ah(special order) but wanted to try to series parallel because of the ah bump. Any configuration for that? If not I’m guessing my batteries will not put out/last as long. Any help is appreciated.

By: Chad Smith

Chad Smith — Sat, 24 Feb 2024 10:42:53 -0800

For a project I'm working on, I need to wire up two batteries for 24v power. Ideally to make things work, I would need to have the batteries about 5 feet apart. Does that work for a series setup and if so, how do I make that work properly? What type of wire should I use?

By: Jeremiah Diano

Jeremiah Diano — Tue, 20 Feb 2024 20:24:19 -0800

hi there i want to run my above pool water heater 15 amperes 220 volts on either battery on in solar panel thanks for your advice

By: Louis Makala

Louis Makala — Mon, 19 Feb 2024 02:47:58 -0800

Is it possible to use solar panels to vision batteries of 2×100ah and gel battery of 100h together?

By: Quentin van Niekerk

Quentin van Niekerk — Tue, 11 Apr 2023 02:52:03 -0700

Hi there, I have 72V ups 3kVA using 6x 12V 7Amph batteries connected in series. I changed the batteries to 200Amph, but the UPS does not charge the batteries enough. Can I make use of a 24V charger to charge 2 batteries in series on the 72V bank and then a 48V charger to charge 4 batteries in series on the 72V bank? Do I need a diode between 24V and 48V banks to isolate?

By: partick mcmillan

partick mcmillan — Tue, 28 Feb 2023 06:51:53 -0800

I'm confused..in your diagram of series and parallel...you show positive of one set (TWO batteries) connected to negative of the other set....in addition to the pos and neg wired in each set....never seen this confiquation before

By: Richard North

Richard North — Sun, 01 Jan 2023 07:14:02 -0800

My deer cameras use 8 AA lithium batteries, and typically all 8 measure 0 or nearly 0 volts when I change them; but sometimes one has the same voltage as when new. How is this possible? Are these batteries worth saving for re-use? If all 8 were in parallel and one made poor contact, this would explain things, but this cannot be the case as the battery pack comprises 4 columns of 2 batteries physically is series end-to-end. (I haven't traced the circuit within the pack, nor have I measured its output voltage, and I plan to do so, but even after I do so my questions will remain.)

By: Mathias Maul

Mathias Maul — Mon, 28 Nov 2022 15:12:43 -0800

How do you change a series-parallel configuration if I’m using 4 12v 7Ah lithium batteries?

By: Sekani

Sekani — Sat, 24 Sep 2022 10:51:23 -0700

Which one as the highest running hours? (1) 3000W inverter 24V system, using 4 batteries Of 12V/220Ah each, (24V/440Ah ) series -parallel configuration (2) 3000W inverter 48V system, using 4 batteries of 12V/220ah Each, (48V/220ah ) Series configuration. Note - both inverters are running on same load.

By: Trent Peters

Trent Peters — Wed, 03 Aug 2022 18:13:04 -0700

In 3 battery 36v series is there a battery what works harder than the other batteries?

By: Aguanieso

Aguanieso — Wed, 17 Nov 2021 04:45:52 -0800

Is it required to install a 24V battery system when solar panels have 18V to 22V rating? or 18V panels need a 24V solar battery system?

By: PAUL KAMPA

PAUL KAMPA — Wed, 03 Nov 2021 06:30:47 -0700

I'm running a 24vdc system on my boat. I have two 8D batts in series for the engine and two group 31 batts in series for the house. I currently have a 12v, 60 amp, 4 bank charger. One output leg from the charger is connected to each battery. Therefore I am getting a 15 amp charge to each pair of batteries. The engine batts get an adequate charge but I find that I have a max load of about 30 amps on the house. I am normally using a generator to power the charger/batteries and the charger is not keeping up with the load. I am considering options and one is to add two more grp 31 batts, which would have to wired in series for 24 vdc and in parallel for additional power as per your drawing? That would provide me with 24 vdc and 200 Ah. Can I use my existing 12v/60amp/4 bank charger to increase my charging amps to 30amp at 24v? How would that be wired? I am considering a new charger at 24v/35 amp but with only one output. How would I connect that to the 4 x 12v series/parallel configuration to achieve 35amp charging? A friend suggested using 4 x 6v batts in series to get 24v/200Ah and getting a new 24v, 50amp charger. I have not found a 24v, 50 amp charger with a 120 vac input but I found one at 24v, 35 amp. Is this a better way to go? thanks

By: Ray Velez

Ray Velez — Sun, 31 Oct 2021 12:45:52 -0700

I have 10 MK gel 40AH batteries, I would like to use an 3K watt inverter back up on what size wire and what wiring method of wiring should I use, also what size trickle charger would I need for batteries? Thank You

By: James Arthur Lugg

James Arthur Lugg — Sat, 09 Oct 2021 15:00:54 -0700

I have 2 six volt AGM batteries in series for the cabin of our Roadtrek that are in the engine compartment and are charged with three solar panels on the 5e roof of our rig. Would there be any advantage with replacing those batteries with two 12 volt LiFePO4 batteries wired in parallel?

By: Chris

Chris — Mon, 04 Oct 2021 18:42:29 -0700

I am looking at a 24V lithium system for my trolling motor,. I have planned to purchased two 105A/h lithium battery but have since seen a single 24V battery which would actually save some time and cost in modifications to store the battery's. The physical dimension of the 24V battery is not much more than a 12v battery so I am wondering what I will loose/gain between the two options. I am not an electrics expert, so my brain would think along the lines a 20L bucket(two battery) of water vs a 10L single battery) bucket of water. drill a 3mm hole in each- the water pouring out is equal in each but the 20L bucket will last a lot longer. Am I on the right track with how this compares to the two battery systems mentioned above. Thanks

By: Mauritz

Mauritz — Wed, 08 Sep 2021 05:20:04 -0700

When I connect batteries in parallel and run it, will it take longer to charge it again?

By: Chris

Chris — Mon, 15 Jun 2020 14:13:42 -0700

I have a small solar off the grid system with inverter and I initially purchased a 12V deep cycle battery for it, a couple months ago my neighbor offered me (2) fairly new 6V batteries from his camper he happened to get through a warranty issue with the OEM. Can I connect the (2) 6 volt in series, and then parallel into the 12V or are there concerns with combining 6V & 12V batteries together? I thought this would be a cheap way to expand my overall battery storage but want to make sure there aren't any issues I'm not aware of. I would appreciate any feedback you would have. Thanks

By: Matt

Matt — Fri, 05 Jun 2020 15:07:46 -0700

Can I wire 2 batteries to my inverter separately

By: nick miller

nick miller — Sun, 31 May 2020 18:43:09 -0700

can you hook 2 12 volt batteries in series and parallel with 2 battery on / off switches? obviously with both switch off while changing from series and parallel? im trying to be able to switch from series to parallel with 2 on / off switches(one switch on while the other is locked and off) and only change voltages while both switches are off im trying to run 2 different voltage requirements obviously never at the same time but for depending on what i need be able to change from combined 12 volts to a single 24 volt. and also where would you want to wire in the switch?

By: Frank Taylor

Frank Taylor — Sat, 30 May 2020 05:46:39 -0700

Can you wire 3 sets of batteries (already wired in series) parallel? 6 x12v batteries to 24v. Will that triple the ah?

By: Ilyas nisar khan

Ilyas nisar khan — Sun, 24 May 2020 22:39:51 -0700

I have two 12 volts batteries can i join it with different chargers ?

By: Saru

Saru — Sat, 23 May 2020 16:11:50 -0700

If I have a 36 volt 20 ah battery that has a 1 c-rate and I use a 12 volt step down convertor to make it 12 volt battery am I okay using trolling motor with a max 60 amp draw?

By: David Brakefield

David Brakefield — Thu, 21 May 2020 16:26:22 -0700

I have a 24 volt battery system on my bass boat for the trolling motor. I started getting a callcium substance building up on the back of the power head. I then noticed small amounts of the same thing speckled (embeded) on the metal jack plate and the face of the on board electronic sonar face plate. A mechanic said the dealer installed the grounding system wrong. What is this called and how is it possible?

By: Nathan

Nathan — Mon, 11 May 2020 23:44:11 -0700

Can you explain why it's better to connect loads to opposite batteries in a parallel configuration? If both will still drain mostly equally if loads are connected to the posts on just one of the batteries, what is the advantage of connecting the positive to one battery and negative to the other? Really helpful article, appreciate it.

By: Lore Christensen

Lore Christensen — Mon, 11 May 2020 17:19:45 -0700

I have 12 volt system system for my off-grid home. The system is comprised of four 12 volt batteries wired in parallel, a charge controller and an inverter. I’m confused which batteries to connect to the charge controller and the inverter. Seems most diagrams don’t include the connection points for BOTH the charging and discharging sources. Thank you.

By: Patrick E Allen

Patrick E Allen — Sun, 19 Apr 2020 13:30:59 -0700

how many BMS i need for 10 parallel batteries?

By: Patrick E Allen

Patrick E Allen — Sun, 19 Apr 2020 13:25:24 -0700

i have 10 100ah lithium batteries, to connect to the all in one vicron inverter. do i parallel all 10?

By: J.P.

J.P. — Sat, 18 Apr 2020 06:12:28 -0700

I am thinking of running two batteries in parallel on my son’s power wheel to increase the run time. If I wanted to install a battery meter gauge would I need two gauges, one for each battery, or just one? If it is just one, would I only use a 6v (using your example above)?

By: jake

jake — Wed, 15 Apr 2020 00:46:26 -0700

i want to connect a deep cycle battery to my starter battery on my van with a split relay system between, i have a varta 80Ah starter battery, does the deep cycle battery also have to be 80Ah or could it be 70 Ah or a 100Ah deep cycle battery and does it also have to be the same brand?

By: John orman

John orman — Tue, 07 Apr 2020 03:18:05 -0700

I have 14 6 volt batteries should I run them 12 or 24 volt and how do I hook them up

By: Bryce Ballantyne

Bryce Ballantyne — Sun, 05 Apr 2020 05:43:12 -0700

I have a pop top van that will be running 2 deep cycle batteries in parallel. They will be charged via solar with a generator for backup. I will be running an inverter from the batteries with one battery on the positive the other the negative to evenly disperse the power. My question is both my batteries are in battery boxes. Both boxes have 2 Anderson plugs and external terminals. Can I join both in parallel via the external terminals? Also my solar panel is capable of charging both and has 1 Anderson plug. Will it evenly charge if plugged into one box or like the outward power do I need to put positive to one battery and negative to the other.

By: Nate

Nate — Sat, 04 Apr 2020 18:56:38 -0700

With a series-parallel, would it be beneficial to still go from + of B1 to - of B3 and - of B2 to positive B4? Or is that just best practice for a connecting a load.

By: VIGHNESH BOSE

VIGHNESH BOSE — Mon, 23 Mar 2020 20:04:41 -0700

I have a bus and it have a 12 v battery .if i connect one more 12 v battery in parallel to increase the storage, Will it damage the wiring or alternator of the vehicle?

By: Kirl raphael

Kirl raphael — Thu, 05 Mar 2020 10:07:18 -0800

Very useful information.. thanx alot

By: Bandura

Bandura — Mon, 02 Mar 2020 04:24:48 -0800

I need to use a battery to power a 48v 1800w motor for a project. The motor has a rated current of 33A. What will that mean for the battery? I have found a battery that has maximum output of 10A. What does that mean? Does it mean the motor won't receive enough power, or will the motor be fine and still work to 1800w. The controller for the motor also has a current of 38A, so does it mean it's the max it can withstand, or the amount it works at? with all this information, what would you recommend i use as a battery?

By: Anthony

Anthony — Sun, 08 Dec 2019 16:53:53 -0800

HELP! I have a stand alone 24v solar gate set-up (no access to mains power) My 2 x 12v 7.2Ah batteries don't seem to hold enough charge over night. They're charged by 1 x 20w Solar Panel. First time use in the morning has the Voltage at around 21-22v which wont even power on the gate circuit board yet alone open/close the gates (this is according to the display on my 24v, 10amp Solar Controller) What should I do here? Wire 4 x 12v 7.2Ah bats in a join series/parallel set-up to produce 10amp 24v output? Increase the Solar Panel size? Or do both??!!

By: Michael

Michael — Thu, 05 Dec 2019 16:57:19 -0800

I am installing a 12v deepcycle battery with an inverter to my truck. I have a Multi Battery Isolator for it. And I'm using the charging wire that goes to my battery in the truck for the isolator. Should I ground the deepcycle to the frame or will a body ground work? And is this the right way to do it with the truck alternator charging both?

By: Levi

Levi — Mon, 02 Dec 2019 16:39:55 -0800

After reading this it seems that parallel is a better way to go when you want longer run times. I.E. I have a houseboat and was running one 12v deep cycle battery for the interior lights. I was told to buy two 6v batteries and run them in series for longer run times. If I’m reading this correctly, that is not the case. I would be better off running two parallel 12v batteries for more AH. These batteries are separate from my starting batteries and only run the 12v lights, radio, power to propane igniter on fridge and hot water tank. Is that correct?

By: Steve Kohn

Steve Kohn — Tue, 14 May 2019 13:47:41 -0700

Wonderfully clear explanation. Many thanks.

By: Readone

Readone — Wed, 08 May 2019 12:42:49 -0700

Thanks very so much it helps me alot

By: Vickie

Vickie — Wed, 17 Oct 2018 08:57:32 -0700

Thank you! This is just what I needed to know to set up the battery bank in my RV. The batteries were gone and no schematic.

By: CampRicco

CampRicco — Wed, 22 Jun 2016 09:15:29 -0700

I have two battery banks. One stationary (12v/140ah) and one portable (12v/25ah). I want to be able to plug portable bank into stationary bank for charging. Should I be concerned about the inrush current when connecting portable bank into stationary bank while battery charges are equalizing. Can a resistor be added to cable to slow current while banks are equalizing. If so where in connection and what value would you recommend.

By: jim k

jim k — Sat, 18 Jun 2016 04:25:11 -0700

Good morning, I have 2 batteries connected together to make 24 volts for my trolling motor.My question is can I use 1 battery for my outboard for a 12 volt starting and charging system without disconnecting the 2 batteries. thanks for any response jim

By: Daniel Mangiardi

Daniel Mangiardi — Fri, 17 Jun 2016 22:22:19 -0700

You guys are awesome! Thanks for all the info. Tech and Jeremy Fear have thoroughly answered a lot of great questions. They should be promoted and given a raise. Seriously. This kind of customer service earns business and demonstrates professional prowess. Again, thanks for all of your help! One can learn a great deal perusing some of the questions and solutions in this thread. Sincerely, Your Future Customer

By: Adam

Adam — Wed, 15 Jun 2016 06:12:48 -0700

I have 6 1.75 v lead batteries that I got from a electric plant that is being torn down how would I wire them up to produce 12v or 24v

By: Mike

Mike — Thu, 09 Jun 2016 09:41:53 -0700

Could I set up another 4 12volts 20 ah battery in my 48v but make them parallel to my 4 existing batterys would that keep it at 48?

By: Jerry Hamilton

Jerry Hamilton — Wed, 08 Jun 2016 13:37:51 -0700

I have 4 identical 8 volt batteries can I use all 4 in a 24 volt system? I was thinking that I can put 2 batteries in parallel and put it in series with the other 2 and get 24 volts. 8 V series (8 v parallel 8 v) series 8 volt. It should equal 24 volts but I’m not sure what it would do to battery life and charging. Has any one tried this?

By: Marcus

Marcus — Thu, 26 May 2016 03:54:19 -0700

Hi There, I have bought a 30 year old boat that has two banks of three 12v 75Ah batteries, two are connected in series and one in parallel. The system is 24v so I understand that this is being achieved by the two in series.I realise that this is a very bad set up and I should have four batteries with two banks connected in series and then joined in parallel (something I will be updating). However I seem to have an extra problem, when left with the main breaker switch off the two connected in series slowly loose their charge. Is this due to the bad setup or is it likely to be a drain somewhere? I would have thought that if any of them were to drain it would be the one in parallel. Any advice would be greatly appreciated.

By: James Cook

James Cook — Mon, 23 May 2016 09:18:34 -0700

All of this makes my brain hurt. Here’s what I’m trying to do. I have a RV with two 12v 100 amp batteries, giving me only 200 amp hours to run the RV. I want to remove them and add eight lithium 12v 100 amp batteries, to increase my battery bank to 800 amp hours, and I also plan to add solar charging so I don’t have to run the generator so often. How should I wire these batteries together?

By: matt

matt — Sun, 22 May 2016 04:48:11 -0700

Can you please help solve this mystery fot us? Our cabin has one 24v 100A panel with mppt charger.
We have 2 × 105Ahr batteries, less than a year old. Thinking of adding a 3rd due to them draining quickly from the refrigerator turning on and off all day.
Is a 3rd battery going to be ok on the system? We are only here couple times a month so we don’t care how long they take to charge.
Thank you!

By: Scott

Scott — Thu, 19 May 2016 10:40:50 -0700

I purchased a rare vehicle that requires 24V to the engine but the other electronics are 12V. It has two identical rather new 12V batts in series and after sitting a few weeks went dead.

I removed the leads to charge each batt separately with my 12V charger. When first testing each one with a volt meter one had a normal polarity and 12V, the second batt had 10V and reversed polarity coming from the posts. Is this because the second batt is failing, is it normal to have a reverse polarity memory on the batt with positive to the neg post? Or if both batts are perfect should the second batts have normal polarity on the charge? Thank you in advance.

By: Jason

Jason — Mon, 16 May 2016 16:47:37 -0700

I am trying to run my camper off solar. I have calculated 600w per hour at max, 70A per hr at 5 hrs. I have currently 2 12V batteries in parallel with 70ah’s. I have The harbor freight 45w solar panels, and a 1500w continuous inverter I have read article after article and I just can’t figure out exactly what I need to do. Please help me. And thanks

By: Mike

Mike — Wed, 20 Apr 2016 06:57:26 -0700

I am going on a family vacation with a bunch of family members. I have four batteries that I wanted to connect together and use an inverter so that I have Outlets for people to charge their phones. How should I wire them up series or parallel or series parallel? I wanted to hook them up to my car battery so that I can charge them at some point during the day. Which way would last the longest without causing harm to my batteries?

By: Olugbenga

Olugbenga — Sat, 16 Apr 2016 20:43:07 -0700

Hello Tech,
I have a battery of 12v,200amp that lasted for 4-6hrs with a 0.5kva inverter, I got an extra battery connected it IN parallel but not a difference in output after achieving 12v,400amp. I thought I’ll get more back up hours what could be the problem.

By: Rob

Rob — Thu, 14 Apr 2016 07:54:54 -0700

Wow I do not know how you’ve done this! It seems like a huge time investment and I REALLY appreciate your dedication. Kudos are not enough. Thank you for this….especially the truly weird and wonderful people asking the same questions multiple times. Your tech staff must have some wonderful discussions at break time. See the internet can be amazing at times. I bow and salute experts that really are experts. Refreshing. Rob H

By: Saby

Saby — Mon, 11 Apr 2016 07:45:48 -0700

pls…help me…can a 2v , 300Ah battery be replaced
with a 2V, 200 Ah battery for a 24V, 300 Ah capacity battery bank?

By: Owais

Owais — Fri, 18 Mar 2016 11:45:43 -0700

Dear fellow, i have a simple query but a lot of confusion. I have two 12 v batteries (250 and 200AH) connected in series to a 24 V solar inverter. M not happy with its charging and output. I thought that might be the different amperage is the problem, and after viewing this article my confusion increased. So plz plz plz tell me what should i do, so tht i can save my valuable batteries and inverter. Thanx

By: Pete

Pete — Thu, 11 Dec 2014 17:32:29 -0800

I have a 800VA inverter, with one 12v 200amp battery. I just bought four 12v 100amp battery. Cant I connect all 5 batteries to give a 12V 600amps???

By: Dave Smith

Dave Smith — Tue, 09 Dec 2014 16:24:14 -0800

I want to power a freezer at a research station in a fairly remote part of India. The freezer draws 4.5 amps at 115 volts. Grid power is intermittent and I plan to use a diesel generator for most of the off-grid power, but as the samples in the freezer cannot be allowed to defrost, I want to have a battery back-up system in case of fuel shortages, breakdowns, etc. Does it make sense to use a bank of 12v batteries through a 1500 watt inverter to power the freezer? If I connect a charger to the grid and then to the batteries, would the charger have to be disconnected when the batteries were being used? I could use a manual switch to go from the generator to the batteries. Sorry but I haven’t figured out the amp/hour thing for sure. How many amp/hours would I need to operate the freezer for, say, four hours? 115/12 × 4.5 × 4 = 173? With some extra added for inefficiency, starting, etc. so say 220?

Thank you for this very valuable service.

By: biron

biron — Sun, 07 Dec 2014 00:59:48 -0800

i have a 24v system am using two 12v batteries connected in series but i notice one of the batteries discharging faster than the other what is the cause of this problem and how will i amend it

By: Moe

Moe — Thu, 27 Nov 2014 12:09:46 -0800

Need some input please…I’m a truck driver and my truck is currently running 4 12v batteries in parallel. I wanna add 4 more batteries to the circuit of 12v each to increase amperage. All 8 batteries are the same. I’m aware that voltage will remain the same if all 8 hooked up in parallel and amperage will double. Question; will the increased amperage hurt any of the components in my truck, or is the extra amperage just being stored for easier engine starts and longer running components (like fridge, microwave laptop,…) without idling the engine?

By: Kevin

Kevin — Tue, 25 Nov 2014 15:45:32 -0800

I have 1 × 12v 120a/h AGM Battery and 1 × 12v 94a/h AGM battery in my caravan that I wish to connect in parallel.
I will be using a DC-DC C-tek charger or AC-DC C-tek charger depending on where I am.
What issues will I face charging these batteries together when connected in parallel because of the different capacity ratings?

By: Chidi

Chidi — Wed, 19 Nov 2014 03:27:50 -0800

Hi, I have 1.5KVA Inverter four 12v batteries. I want to increase the output voltage of the batteries to 24v(which is what is required as the input of the inverter) and also triple the Amp-hours so that my power output will last longer. I was thinking, can I connect two of the batteries in parallel thus doubling the amp-hour and keeping the voltage constant AND then connecting connecting them in parallel to the remaining two batteries which are connected in series. The output that enters the inverter now comes from the terminals of the batteries that are connected in series. will that give me my desired output?

By: Nat

Nat — Tue, 18 Nov 2014 00:38:20 -0800

Hoping this is a simple question. I’m a trucker and my rig has 4 12v batteries configured to operate at 24v. I was given a 12v, 5000w inverter(overkill for my needs but free is free) and wish to install it properly. I believed I had everything I needed but was concerned about the fact that the inverter is 12v while the battery bank is 24v. I assumed it would be fine just to connect to one of the batteries but read above that doing so can reduce the longevity of the entire bank. However another post mentioned a 24v to 12v step down converter. What do I need to look for to purchase the proper converter for my system?

By: Michael Dawson

Michael Dawson — Sun, 16 Nov 2014 17:11:07 -0800

I have 36, 2 volt batteries, wired to give me 12 volts for my home solar system. My 12 volt inverter just died and my new inverter is 24 volts. What is the best way to wire my bank to give me 24 volts. Thanks so much.

Michael

By: James

James — Mon, 10 Nov 2014 15:02:38 -0800

Hi – I’ve got a small bank of 3 12v (total 300ah) batteries in parallel to provide lighting and some other power for small electrical devices (via a 240v inverter) for when we the power is out – they are kept on a trickle charger all the time at 100%. We had a power outage today for about an hour, I was only running 2 low voltage lights for combined draw of about 25 watts for about 60 minutes (0.1 amps at 240v), When the power came back on I hooked up the charger and it said the battery bank was “Low” the voltage reading was 12.4v when I started it charging again. Is this right, even with the (in)efficiency of the inverter factored in, by my reckoning I should only have used about 3ah of bank’s capacity?

By: Joseph

Joseph — Sun, 09 Nov 2014 20:58:04 -0800

I have a question. I have two 3.7v 2500 mAh LiPo batteries that I want to run in series. Can I use a 1A 5v usb charger to charge these batteries while they are in series?

By: Paul Croft

Paul Croft — Fri, 31 Oct 2014 17:09:03 -0700

I have 4 X 115ah 12v batteries if I connect them as 2 banks of 2 connected in parallel will I have 460ah and 12v

Regards Paul

By: Dell

Dell — Fri, 31 Oct 2014 01:09:18 -0700

Inherited 18 Kyocera 50 watt panels but they were wired for 24-volt system. Rewired them for 12 volt system and have 8 new 6v golf cart batteries (deep cycle) from Sams. Concern is Centech 2000 constant 4000 peak inverter from Harbor Tools states in directions NOT to use batteries in series. Is this just an overprecaution? Can I wire two banks of 4 in series and connect to + and – terminals on each end with inverter terminals? Need to power a 5th wheeler at night and air compressor for air tools during day and two deep freezers. Also, are 30 amp fuses/shut offs between panels and Trace controller and between Trace controller and battery bank and battery bank and inverter sufficient? Thanks

By: Ninh

Ninh — Thu, 16 Oct 2014 13:13:45 -0700

I have two 12V batteries in parallel. If I want to “manually” isolate one battery (used for accessories) from the main battery (used to start car) when the engine stops running. What do you have to do this task and when should I install the isolator? I ready about some automatic isolators (solenoid type) that I do not want to get involvaed with and is looking for something manual and simnple.
Thanks,

By: Scott

Scott — Sun, 12 Oct 2014 14:12:40 -0700

Hello… Love the site! I have 2 2volt deep cell golf cart batteries (one Trojan, one Interstate) I used in my previous rv. We just bought a new rv and it has one 12 marine/rv battery in it. Can I connect my 2 6 volt and the 12 volt for an overall 12 volt output? If so who is this accomplished?

Thank you

By: aene

aene — Fri, 10 Oct 2014 05:33:41 -0700

i have 3, 12v batteries that have 7ah for each (sealed lead acid battery).
i have a charger that is rated for 12v batteries 20ah-80ah.
im using the 3 batteries in parallel, and that gives me 21ah.
can i charge them with this charger???
or it will cause them to blow.
thx

By: Ray

Ray — Tue, 07 Oct 2014 11:00:20 -0700

I recently was given a 40 battery bank of Monolite 6 volt sla 100 amp hour batteries, connected in series/parallel to create 12 volts. I only want to use this for storage incase of a power failure. My question is, what type/capacity of charge controller should I use to keep them topped off? I would be using grid power for this, but would like to eventually like to switch to wind/solar in the future.

By: JB

JB — Sun, 05 Oct 2014 10:00:04 -0700

Looking for proof of concept validation before I start cutting and crimping cables:

System will consist of 3 banks of: 4, 12v, 40 Ah LifePO4 Lithium batteries in series for a 48v, 40 Ah bank; all banks will then be run in parallel to bring amp-hours up to 120 Ah at 48v.

To charge the system, I will attach a 48v, 25 amp charger to the central, end lead. Charger and batteries are BMS controlled.

System powers a 3.5 KW electric drive aboard a small sailboat.

Main concers, other than sinking to boat of course is; will this work? Where should I add the fuse(s) (at the end of each bank (150 AMP?) or one at the very end (200AMP?))?

Total novice and dangerously not as intimidated as I think I should be…

We would require more information about your situation. Please contact one of our techs at tech@batterystuff.com.

By: xlr8

xlr8 — Sun, 07 Sep 2014 20:54:32 -0700

I have a sailboat and want to put in a 600amp battery bank for domestic use.
My diesel motor has a 65amp alternator.

What would you use to put this together? 6v or 12v batteries? what type?
Regulator?

What is the best I can do?

By: Dabke

Dabke — Sun, 07 Sep 2014 03:28:46 -0700

one 1 kva 96 v dc/230 v ac UPS having 8 nos 12 v 28 ah batteries. can we add more eight batteries to achieve more ah capacity by series parallel combination ? can this UPS do the proper charging to batteries?

By: CB

CB — Thu, 04 Sep 2014 21:00:27 -0700

Hi there,

I am a beginner in this kind of thing, so this might be a really simple question.

Does the voltage of the battery need to match the voltage of the motor?

For example, could I use 2 12 volt batteries connected in series with a 36 volt 750 watt motor?

Or would I need 36 volts of battery (3 12 volt batteries) to power a 36 volt motor?

Thanks

By: Mike

Mike — Sun, 31 Aug 2014 07:03:15 -0700

Thanks for all the great info that is difficult to find elsewhere! I have a 6000w inverter-powered cabin with two separate battery banks, and one bank appears to need charging more than the other. One bank is 4 12v batteries, the other is 3 12v: it used to be four also but I found one bad one last year and removed it. Do you see a problem here? Thanks

By: camper

camper — Tue, 26 Aug 2014 13:25:35 -0700

Is “2 6volt batteries in series” basically the same as a 12v battery? Can I run a generator the same as I would a regular 12v system? Looking at getting a new camp trailer but am not familiar with the battery config.

By: Giri Manzini

Giri Manzini — Tue, 19 Aug 2014 00:38:55 -0700

Hello
This article successfully answered my question about the parallel battery connection. but i still have a question. 1 have two 12v batteries which i have installed in parallel. i connected the plus and the minus of the #1 battery to the plus and the minus of the #2 battery. i also connected the #1 battery to the solar charge controller. so, can i connect the #2 battery to the inverter? or do i have to charge it to battery #1 too?

By: Admin

Admin — Fri, 15 Aug 2014 14:20:38 -0700

Due to the fact that we don’t have all the information for your system we would need you to contact us at tech@batterystuff.com so that we can ask the appropriate questions, to get you the answer that you may need.

By: Rabbe

Rabbe — Thu, 14 Aug 2014 04:18:55 -0700

i need 2 pcs battery for my machine 12v 2.9Ah but i cannot find those in my country.
is there any other option to chose different battery and that will give me same output.
what is that value of battery plz inform me its urgent.

Thanking You
Rabbe

By: Jim

Jim — Wed, 13 Aug 2014 18:20:28 -0700

Hello and thank you for the excellent article/site. I have a floor machine with four 6 volt batteries wired in series to provide 24 volts. I am attempting to change out 2 of the batteries. I have disconnected the interconnect cables from the old batteries, but I am now getting an arc when I attempt to make the final connection between the batteries. The lead connector from the batteries to the motor is disconnected. Do I need to have the lead connected to avoid this situation or is there something else I can do to avoid arc when making the final connection (maybe discharge the batteries, etc)? Thanks.

By: F-Alli

F-Alli — Tue, 12 Aug 2014 05:27:30 -0700

I have been following up with this thread for a sometime , and i have been enjoying the questions and their corresponding answers.
Pls i have two questions-

1- I have 4 12/150AH batteries , connected in series -parallel, on a 2.4KVA /24V rated inverter .
Please show me how i can calculate the duration it would last if i have an average load of 1000W .

2- How can i integrate a Solar Panel to it the Inverter, to automatically charge the batteries when there is no Public Electricity ?

F-Alli

By: joshua m.

joshua m. — Sat, 09 Aug 2014 06:46:49 -0700

i have 3 12 volt batteries in my car. in front i have a optima red top and the trunk 2 ac delco. i just installed a 400 amp alternator which works when i clamp it or put it under load. but my voltage at idle is at 12.90 and when i rev pass 1000rpms it will go up to 14.9 where i set it. i was wondering if because i have two old batteries in the back and one new in the front if the will be a reason my alternator is reading 12.90 at idle. is it possible because that the batteries in the back are weak and cause a low reading?

By: Fern

Fern — Tue, 15 Jul 2014 20:00:42 -0700

What would happen if I hooked up 2 new DC27 with 3 older DP27 batteries in parallel on my Fifth Wheel camper?

We would require more information about your situation. Please contact one of our techs at tech@batterystuff.com.

By: Michael

Michael — Wed, 09 Jul 2014 16:58:43 -0700

I have 6 12v 100amp batteries wired in series powering a 72 volt motor. I want to charge them all with 500 watts of solar via 12 volt charge controller while leaving them wired in series. My question is how can I safely do this if possible without having to untie the series connections and then rewire the bank in parallel to attach to the controller every time I want to recharge the 6 batteries. Can I theoretically wire a positive/negative connection from the 12 volt charge controller to each battery individually basically charging them up as an isolated 12 volt battery (without having to disconnect the series connection.. and obviously the motor is not running and I have no 72 volt load while this is happening).. or better yet I pull a positive and negative wire from each battery to a separate bus bar that will now be 12 volt and connect the controller to that bus bar to charge all the batteries at the same time even though they are all still connected in 72 volt series as well that is not pulling any loads?

By: Shannon

Shannon — Wed, 09 Jul 2014 05:51:45 -0700

I have two 24V lights and a 24V winch I would like to put on my pickup. If I take two 12V batteries hook them in series to power the 24V accessories. Can I charge each battery with my 12V alternator if I wire them on there own circuit without doing any damage to my truck? Thanks

We would require more information about your situation. Please contact one of our techs at tech@batterystuff.com.

By: jonathon

jonathon — Sun, 06 Jul 2014 16:53:25 -0700

I have an RV with 6-6 volt batteries connected in series. The top of the battery says 232AH. I am wanting to install a refrigerator that uses 445 kWh/yr. How long will my batteries support this until they die?

Thank you!

By: Dragan

Dragan — Wed, 02 Jul 2014 06:21:23 -0700

Hello! I need help. I have a 700VA UPS with AVR that I use on a daily basis. Can I plug it into a 12V solar charger to charge it? Battery inside UPS are 12V 10Ah. I plan to drill the chassis of the UPS and connect solar controller and solar panel 12v directly to the battery, not moving the existing wires. Is it safe to do something like that?

We would require more information about your situation. Please contact one of our techs at tech@batterystuff.com.

By: Kory

Kory — Mon, 30 Jun 2014 17:54:29 -0700

I have an RV with 2 identical Interstate Batteries 12V wired in Parallel. Last weekend we were plugged in, so there shouldn’t have been a draw on the batteries. The one that was added in aftermarket really got hot, smelled of sulfur and the other one was fine. Do I have one bad battery or do I have an electrical problem? Both batteries are approx. 2 years old.

We would require more information about your situation. Please contact one of our techs at tech@batterystuff.com.

By: Rizqi

Rizqi — Mon, 23 Jun 2014 10:00:38 -0700

I have 3 battery with 12V 75Ah and 1 battery with 12V 80Ah. is it possible if I install those 4 ea (all) battery with serial connection ? is it safe ? or it will make damage the battery.

Thank you.

By: John

John — Sat, 07 Jun 2014 16:43:23 -0700

I have a battery pack with 2 aaa’s connected in series to make 2.4 volts 800mah. Is it okay to connect 2 of these in parallel to increase the current? I see that you can do the exact opposite…Parallel/Series. I need to know if Series/Parallel is okay, too.
Thanks,

By: Ted

Ted — Wed, 04 Jun 2014 08:03:39 -0700

I have bought a used 2004 48 Volt Club Car Golf Cart, It currently has 8, Six Volt Batteries! I want to change to 4 12 volt Batteries? Is this possible and what are the down falls of doing so?

By: Rakesh

Rakesh — Mon, 02 Jun 2014 07:16:30 -0700

I have two x 12volt battries connected in series by 24volt solar charge controller, I requir 12 Volt DC for inverters and UPS separatly. Will it sufice to connect both the UPS and inverter separately to both the battries besides being in series.

By: snazzy

snazzy — Fri, 23 May 2014 22:21:14 -0700

Help me here. I have 16 6v batteries connected in series & parallel to give me 2 banks & 48 volts. My outback system seems to be working fine but one bank of the batteries is always a lower sg so I assumed not as charged. Any suggestions

By: Tech

Tech — Fri, 23 May 2014 14:14:34 -0700

As long as your system is sized appropriately. That would still be 12 volts.

By: John

John — Fri, 23 May 2014 01:12:20 -0700

Hi there!
Can I connect 8 ×12volts deep cell Marines batteries in Parallelle to a 12 volts inverter?I have 4 ×160 watts 12volts pv

Thanks

John

By: david

david — Sat, 17 May 2014 10:25:57 -0700

Hellow ok, i have two diffrent brand batteries, now is it ok to use 1 brand for just volts/series, and the other brand parallel?

By: Richard

Richard — Mon, 12 May 2014 11:34:05 -0700

OK another parallel battery question. I have an external 12V 55Ah battery connected in parallel to boost the life of an internal 12V 16Ah battery in a piece of equipment that draws about 12V 8W 24/7. This all works fine. However if I remove the external battery and recharge the internal 12V 16Ah battery it now does not retain its charge. All batteries are lead acid, the internal batteries are deep cycle and the external batteries are ‘car’ type batteries.

By: Steve B

Steve B — Fri, 02 May 2014 17:42:03 -0700

I just replaced the two ancient, weak Interstate flooded batteries with a pair of Lifeline AGMs. They’re house batteries in my RV and they’re wired in parallel.

I checked the voltage of each battery before installing them (12.82v).

I’m wondering if there’s a way to test the batteries now that they’re wired in parallel. (I got a reading of 14.35v by connecting the multimeter to the RV’s Progressive Dynamics converter, but the number doesn’t make much sense to me.)

By: Charles

Charles — Sat, 26 Apr 2014 23:26:50 -0700

First time at this site and have it book marked.

I’m working on an ebike build.

The drive system will be brushless hub motor at 250 watts 36 volt for the rear axle.

The recommended power power from the battery or batteries is 44V/5Ah at 220 watt hours.

I new to this, but I like to build things. My mountain bike does not have much room for the rather large bulky batteries because it has front and rear suspension.

I’d like to use a bank of smaller batteries instead and arrange them around the frame or in a saddle bag. Some ebikers are using recovered laptop batteries. I like use try the Lipo packs used in remote controlled planes. The batteries come in many different shapes and sizes. How can put together a group to drive the motor at the recommended voltages and to get the best range? Oh, and I almost forgot. I’ll need a good charger. So what would the charge specs be also.

With all of our battery powered needs from cars to phones, DIY is liberating and fun.

Thank you. Charles

By: andy

andy — Thu, 17 Apr 2014 21:56:41 -0700

Thanks chaps, this is a very interesting site.
I found it trying to get some idea of how to prolong the use of sets of used ,half dead golf cart batteries on a stand alone 24 V solar system.This is only a non essential system I play around with having nothing better to do but it still runs my fridge as a bonus!
Currently I have 3 strings @ 24 V connected in parallel.Current draw is 12 Amps max about 18 hours every 24 hours.Some cells discharge more than others (on days with no sun),it automatically disconnects when the Voltage gets to 23.0 Volts.
Now the question I wish answered:where in the string setup should the worst of the cells be and what is the benefit or disadvantage of adding more semi faulty batteries to the system.
Kind regards
Andy

By: shashank sharma

shashank sharma — Thu, 17 Apr 2014 06:17:54 -0700

i have one circuit for mobile charger and one dynamo circuit both of them having different jumper wires can i connect them two the same battery of 12v and 7ah using their jumper cables

By: maurice

maurice — Sat, 12 Apr 2014 20:25:36 -0700

if I have 24 2 volt 540 amp hour batteries in a series does that mean I would get 26 kw of power for my home per hour 48 volts x 540 amps = 25920 watts is that correct

Thanks

By: Jules

Jules — Sun, 06 Apr 2014 17:31:51 -0700

Hi, i have four 6v 225ah batteries I’m installing in my boat, the usual setup seems to be first to series two 6v batteries to achieve 12v then parallel the two series together however your diagram shows paralleling two batteries first then series to achieve 12v, What are the advantages/disadvantages of doing it the way you show?, I’m very keen to set my setup like your diagram given my battery locations – thanks

By: Jules

Jules — Sun, 06 Apr 2014 17:29:25 -0700

By: sunil vijaya

sunil vijaya — Sun, 06 Apr 2014 02:43:50 -0700

i wonder whether you can help me a solar power set up. i have a hybrid home with 6 panels each 80w 18v 4.45amp. i have 4 agm batteries 2 – 90ah and 2 – 70ah. i need to power my air con which is 930w 9000 btu. what is the battery bank i need? can i increase the solar panels output and keep the same battery bank?

By: Helen

Helen — Fri, 04 Apr 2014 00:49:51 -0700

Hi
We have 24 batteries 2 volt each just wondering I what sort of charger we would need to charge
Thanks

By: Stacy Kermode

Stacy Kermode — Wed, 02 Apr 2014 16:26:53 -0700

I bought a Travel Trailer in February they stored it for me until April 01/14, when i got it home i noticed the batteries wont power anything on trailer.(Two 12volt deep cycle batteries wired in parallel)its now sping but still cold. Are my Batteries now crap or can they still be charged and if so do they need to be charged separately or can they be charged together and how? do they need to be removed from trailer or can i charge them on trailer? do they have to be warmed up first and how long? SORRY for so many questions but im worried about them. Any help would be greatly appreciated! THANKS!!!!!

By: mike cooper

mike cooper — Thu, 27 Mar 2014 04:29:31 -0700

Hi, Found this site/thread researching charging rate/outputs for a leisure battery. What a good site.!!You solved my problems. A BIG THUMBS UP.!!

By: Ryan

Ryan — Thu, 20 Mar 2014 08:55:25 -0700

I have a NOCO Genesis (1bank) battery maintainer/charger. However, I have two batteries wired in series with a blue seas system switch. My question is, can I wire this charger to maintain both batteries or only one? Also, how should I wire it with the switch to get both if possible?

Thanks,

By: francie

francie — Mon, 17 Mar 2014 18:42:37 -0700

if my total battery capacity is 2000Ah, but my specs states that the battery bank is 2 × 50% does this mean i will be using only 1000Ah? thanks for the response.

By: Kaye

Kaye — Sun, 16 Mar 2014 13:16:18 -0700

So if I need to charge my discharged battery, what would be the ideal way to connect them? In series or parallel?

By: John Prowse

John Prowse — Tue, 11 Mar 2014 19:32:16 -0700

I have a mobility scooter with 3 × 12v batteries wired in series to give 36v. I want to go lithium, but have been told that the battery management system won’t allow a 36v charger to charge a bank in series, and that I would have to charge each battery independently with a 12v charger. Does that sound right to you? Thanks for all the info in this article, by the way. Very useful indeed.

By: Danny M

Danny M — Sun, 09 Mar 2014 07:00:52 -0700

Im trying to get my son’s 91 Club Car to go a little faster. We recently purchased/installed 6 new Trojan 6v batts. Found the cart very slow up hills, decent on flat surface and very fast downhill. I have several questions, please: Someone told us we could replace 2 of the 6v batts with 2 8v batts. I did this, but accidentally crossed up the cables when putting in the new 8v batts (i.e., I hooked up the NEG from batt #3 to the NEG of batt #4, etc.) Then I ran the charger overnight. Did I hose the batts in any way by connecting improperly? I tested the cart the next morn and it was terribly slow, so I checked the cables and found my error. So, I reconnected properly (each NEG to the next POS in a series, etc.) and charged the cart again until the charger shut off. Again, we have nothing – slower than slow on flat surface, wont climb hills at all and wont move in Reverse. Now they are saying it must have been a charging problem (with mixed batt voltages)and say we should replace all of the 6 6v batts with 5 8v batts and still use our 36v charger. They said that by having 1 less batt and 4 more volts it would help the cart go faster up hills… Will this work? Is this worth the change? What Im most worried about is: Will the 36v charger fully charge the 5 8v batts? Should we just stay with our 6 6v batts and be slow up the hills? Thanks much! Im novice at this golf cart maintenance thing and want to help my son. DM

By: trapper

trapper — Fri, 07 Mar 2014 23:41:49 -0800

i have 4 3.7v li-ion batterys if i putt them in para/ser would that run a 5v bluetooth chip two low volt amp chips and about 30 leds andd maybe a circut or twwo more or do i need to do one or the other

By: Gordon

Gordon — Sun, 23 Feb 2014 10:23:43 -0800

Thank you very much for being available to help those of us who are weekend techs with our toys. After reading your article and responses, I hope that I was correct in setting up my 2 dual purpose marine batteries (EverStart Maxx Group 24 (Model MAXX-24DC))in parallel. My purpose for parallel was to provide powerful cold cranking and marine cranking amps while having plenty of amp hours for my tilt/jack plate/GPS/gauges. My biggest question refers to trickle charging this set up. Since these are marine dual purpose batteries joined in parallel, I was wondering which Tender Junior charger I should use to keep them charged? Thank you in advance for your expert advice, Gordon

By: Kenny Schwartz

Kenny Schwartz — Sat, 18 Jan 2014 15:16:53 -0800

Ignore second comment. Just realized that’s not possible with only 2 batteries and am again lost.

By: Kenny Schwartz

Kenny Schwartz — Sat, 18 Jan 2014 14:53:31 -0800

I sent a question comment to you a couple minutes ago and believe I figured it out on my own just now. For the car stereo issue I would do a single battery series parallel setup running the back battery on it’s own seperate parallel circuit then linking it to the front one with a single wire between the two positive posts. That would essentially give me double the capacity without multiplying the voltage or amperage output from creating a bank while keeping them on the same charging system.

By: Kenny Schwartz

Kenny Schwartz — Sat, 18 Jan 2014 13:55:58 -0800

I have a 1000W 2 channel amp powering 2 pioneer 1300W Subs in my car. I’d like to put a dry cell battery in my trunk so I can play my music at car shows without having to start the car or worry about it being dead when I go to leave. Assuming they’re both equal voltage and CCA ratings would I want to wire them in series or parallel and could this cause any issues with say blowing light bulbs or starting fires etc… with the factory wired components or would I have to put a resistor before the fuse box in order to correct the issue and would that negate the benefit of having 2 batteries? Obviously i’d be using somewhere around a zero guage wire for the job.

By: Kirk

Kirk — Mon, 09 Dec 2013 12:13:38 -0800

Thanks for the great info, Tech!

The situation:
Say I’m setting up a 12V house bank for my boat, something like 800 amp-hour of capacity, probably 4 200 amp-hour 12V batteries in parallel. I’ll have an inverter that recommends a 400 amp fuse at the battery. The system will also have a 150 amp alternator for charging from the engine, and a DC distribution panel whose main breaker is 150 amps.

The question:
How do I pick the right size cables for the “bridges” within the battery bank? Does it matter which battery serves as the “top”, where the main feeder is connected?

Thanks for a great resource!

Kirk

By: Gerard

Gerard — Sun, 01 Dec 2013 20:40:10 -0800

I have a 48v golf cart, consisting of (4) 12v batteries. I would like to hook up 12v accessories to it. Is there any problem with hooking the 12v accessories directly to (1) of the (4) batteries? Is a voltage reducer necessary?

By: Dwight

Dwight — Wed, 29 May 2013 21:57:38 -0700

Question, I have a bank of 420 ah,48v (12v 105ah AGM-identical batteries)why is it that I find that over a 3 day period one of the 4 batteries in series have less charge. i.e. 3 has 12.7 and 1 has 11.7v; to prevent me from losing the battery, I have to charge that battery independently, then put it back in series……… work for another 3 days then all over again, any suggestion Tech?

By: Jonathan

Jonathan — Mon, 20 May 2013 14:56:32 -0700

I am working on a backhoe with two 12volt batteries hooked in series to make 24volts. With engine idling one battery is charging at over 14.5volts while the other battery is just under 13volts. What would cause this? The battery that is charging at under 13volts is only 12.88volts with engine off and 12.99volts with engine running.

By: Shujaat

Shujaat — Mon, 20 May 2013 02:13:40 -0700

I have a solar panel with 60V and 10A with power = 600W. I have a stock of 12V and 125A batteries. So Which configuration(series and parallel) and effective voltage of batteries i need to properly charge batteries.

By: Jose

Jose — Thu, 16 May 2013 04:31:40 -0700

I have two separate 120Ah gel batteries in a boat. One is for supporting the single engine on-board, and the second one for all the other on-board services.
There is a switch on the positive (+) that allows both batteries to run in parallel if needed.

The installation comprises a single negative cable (large cross section: 95 mm2) that connects the engine and the engine negative battery pole (Cable NEG A)

A similar AWG cable (Cable NEG B) interconnects the negative poles of the two batteries. The battery charger outputs 12.5A on each of two individual cables connected to the positive poles of each battery. A negative lead is connected to the large negative cross section cable.

My question is the following:
Can I replace the “Cable NEG B” with a cable of smaller cross section (50 mm2) with only a length of 40 cm and use a negative bus bar for connecting the services individual wires?

Basically I can reformulate the question in the following manner: there is any requirement for the negative return between both batteries when they are in parallel to have the same cross section of the positive leads? If so would a minor distance (40 cm) be a big deal considering that a cross section of 50 mm2 can cope with more than 250A of current at 12V?

Your comments would be greatly appreciated and congratulations for a great blog. Thanks

By: Diane

Diane — Fri, 26 Apr 2013 18:07:34 -0700

Thank you for this great blog. We currently have a 48v wind/solar system with 8- 6V 230AH deep cycle batteries in a series. We just purchased 4 more to add to them, exactly the same batteries. The originals are almost new, too (just spreading out paychecks!). Question is, how do we wire them in to add more amps but not add voltage?

By: mark

mark — Thu, 18 Apr 2013 16:13:55 -0700

I have 6 12 volt batteries wired in parallel, trying to create a jump cart for diesel rigs like Peterbilts. It will not jump start the trucks any ideas why and what I could do differently. The trucks are 12 volt systems

By: Wilson

Wilson — Wed, 10 Apr 2013 23:05:42 -0700

Hi, I am currently running two 12V 40 Ah Exide Solar Tubular batteries in 24V solar power system.
I am planning to enhance the battery capacity.
Simple way is to buy two more 12 40AH batteries.

But is it good to build a battery bank like this:

two 12v 40 AH in parallel bank and one 12v 75AH battery in series with it.

I would like to know whether it would create any charging or capacity issues?
I have a 12V 500W panel array.

By: kev

kev — Wed, 10 Apr 2013 01:12:42 -0700

Hi, what happens to the Rated Discharge Current and Max Continuous Current when cells are conected in Parallel? Will this increase in the way the Ah capacity will?

By: Denny

Denny — Tue, 26 Mar 2013 13:20:23 -0700

Wondering about how much voltage/amperage I can put into the batteries. I have 6 × 12v deep cycle batteries in parallel and I know I can charge them all with my 2amp and 12 amp chargers, but could I also charge them with something of higher wattage or voltage. (I have a 190W solar panel that is 36v and it outputs about 6amp.), Can I put 5 of those panels together to get 30amp out of them and still charge the batteries. I could definitely use the energy so the batteries would never over charge. Any pointers would be appreciated.

By: Paul

Paul — Thu, 14 Mar 2013 23:11:38 -0700

By: Paul

Paul — Thu, 14 Mar 2013 18:28:21 -0700

I am replacing battery packs in an emergency lighting unit. 4 6v 7.2ah batteries are needed. the wiring has been removed and I will be rewiring it. the packs drive 4 sets of lights through out my business. I am not sure if I should wire them in series, parallel or combination. the side of the light unit has been marked 12v 200watt by the previous owner. the unit is wired to the building correctly, I just need help on the battery pack wiring. any help would greatly appreciated!

By: eme

eme — Tue, 05 Mar 2013 13:33:44 -0800

Im working on an experiment for an art exhibition. Where i need to power a small 1.5-3volts 0.2amp engine with lemons. Each lemon provides around 1volt and 0.001amp. To lower the amount of lemons that i would need to power the engine is there something to increase the amperage, a capacitor perhaps? thanks!!

By: Fred

Fred — Tue, 05 Mar 2013 10:03:26 -0800

I have a off grid system and have acquired a second battery, First one is a 280AH AGM battery and second one is a 230 AH AGM Battery, Is this going to be an issue to connect the second battery in series to the First, Will it cause any problems, Is there a safe way to connect it if not, Cheers In Advance

By: David McNamara

David McNamara — Mon, 25 Feb 2013 07:18:54 -0800

I have six deep cycle batteries, a 3,000 watt inverter in my horse trailer. I have a 250 watt refrigerator and 2 12 volt fans. How do I connect batteries to get the longest time out of them. I have two 15 watt solar panels.

By: emerson

emerson — Fri, 22 Feb 2013 18:08:04 -0800

Is this ok? 7.2v 6batery AA 500mah cmbine with 8.4v 7 biger than AA1500mah? Plz get bck to me asap b4 itry tnx

By: Andrew

Andrew — Sun, 17 Feb 2013 21:58:52 -0800

I have 11 × 15Ah (12V) batteries and i\‘m looking at hooking them up into a 24V configuration. I was planning on having 2 × 12V banks (one with 5 batteries and one with 6 batteries). Is this wise or would i get a better result just have each 12V bank with 5 batteries?

By: Shoumya

Shoumya — Tue, 12 Feb 2013 23:52:28 -0800

Is there any way so that we can switch from one connection type to the other??

Like I will be connecting two 12V,6A batteries in parallel as power source for my robot..this will give a 12V,12A output.ryt?? Now if i want want to give a temporary boost..i can connect the batteries in series which will give 24V,6A.

By: Jeswills

Jeswills — Tue, 12 Feb 2013 18:38:11 -0800

I have 800VA inverter with 12v and 1 200amp then 2 100amp deep circle batteries connected parallel. One is that the batteries were bit by the rain after i moved from my former apartment where a professional connected it for me. Now i just want to connect it to my 12amp room socket, still parallel but i earlier put d charger clamp positive onto another battery and negative to another and it showed low battery at once after charging it for hours. So now i put d clamp positive and negative to one battery in d bank. Do u think i might have done something wrong?

By: Jordan

Jordan — Sat, 09 Feb 2013 23:47:14 -0800

Hey mate we are buying a bus and doing it up. Franky all this battery mumbo jumbo makes me want to go back to school. We were thinking about having 6 deep cycle 12v batteries in the back of the bus to power a heap of equipment. I was wondering how we would go about bringing that to 240v and how would we charge all those batteries. We thought that we might have something set up from the alternator but that many batteries to charge would take way too long. This plan will be happening towards the end of the year but we are just trying to figure out what we need and dont want to be screwed over by anyone.

By: Gil Bishop

Gil Bishop — Wed, 06 Feb 2013 10:02:19 -0800

Hi, I have an RV with 4-6V/200AH AGM batteries in series/parallel used with a 2800W inverter-charger. I want to add more capacity, but I know I can‘t mix old and new batteries in the same bank. So if I add a separate second bank (with the same configuration), is there a way to have the inverter-charger service both banks, using a manual switch or preferably some kind of automatic load-balancer? Any suggestions or “gotchas” are appreciated! Trying to avoid replacing the large and not-too-old investment in the existing batteries if at all possible.

By: Wasim Sohail

Wasim Sohail — Wed, 06 Feb 2013 09:33:06 -0800

I have load of 500 Watts for 8 Hours. What capacity batteries required for longest life, and how should I arrange them.

By: Ivan

Ivan — Mon, 04 Feb 2013 23:50:25 -0800

Hi, i have my RC Helicopter, but it‘s so hard to buy replacement battery with specs 7.4V 180mAh, now i do have 6-AA 1.2V 2000mAh, if i connect them in series i will have an output of 7.2V 2000mAh, will it burn my RC‘s PCB board(power board), if i increased the mAh? or it will be okay?

By: Paul Z

Paul Z — Sat, 02 Feb 2013 14:39:44 -0800

Happy Ground Hog day! I live off the grid and have a 48V system consisting of 8 L16 380AH batteries strung in series. One of the batteries died the other day. As with others above, I hate to spend $3,000 on new batteries because one has died. Can I replace the one L16 with 2 cheapo 6V 225AH batteries in parallel, then connect them in series with the remaining 7? If I understand correctly, the 2 cheapo\‘s will never fully charge and will be stressed more than the other batteries. But if they extend the life of the remaining 7, by a year or more, it will be well worth it.

I was able to adjust my outback solar controller and inverter to handle the 42V system I\‘m running with 7 batteries, but I\‘m not sure if this is putting any stress on those components.

By: Sajib

Sajib — Sat, 02 Feb 2013 13:29:14 -0800

Hello
As in text book we can see two DC batteries/Sources are connected in series,while the one is of reverse polarity of the another ( that cause to establish two currents with opposite direction of each other). Under such a series connection, the resultant voltage is measured by subtracting the lower voltage from the higher one. And finally direction of current can be determined after we calculate the resulting voltage.
Now, I wonder whether such a series connection is experienced in our real life, or such a series connection of sources can damage the device (I mean negative terminal of one Battery is connected to negative of another battery OR the vice versa )?

I would appreciate your time answering me.

Regards

By: Tom C

Tom C — Sat, 02 Feb 2013 07:00:36 -0800

I have two 12 V batteries in my boat with a shorepower charger. Recently both batteries were completely dead. I check shroepower and had 120V to the charger. Charger output was 6 V rather than 12 V. Could this actually drain my 12 V batteries?

By: Bob

Bob — Wed, 30 Jan 2013 23:47:01 -0800

I would like to know what it would take to run an average house in deep cycle batteries,inverter,and charging source.say 180 amp service.

By: Mick

Mick — Tue, 29 Jan 2013 10:21:48 -0800

Very good info and great answers

By: Mick

Mick — Tue, 29 Jan 2013 10:20:20 -0800

Very useful information. I have a question.
When you have 10 6 volt 220a/hr batteries and you want to to have a 12 volt bank which is a better way to connect them, in series banks of 2 batteries each then connecting them in 5 parallel banks or making 2 parallel banks of 5 batteries each and putting those 2 banks in series? Both ways give you them same A/hr output and 12 volts.
Thanks,
Mick

By: kelly

kelly — Mon, 28 Jan 2013 04:50:02 -0800

how many car batteries do i need to run a house using 2000 KwH and what size of an invertor do i need?

By: paul

paul — Sun, 27 Jan 2013 05:33:56 -0800

Hi is it possible to have 12 volts battery‘s configured as 24 volts but still charge them with 12 volt solar panels ?

By: kev wren

kev wren — Sun, 27 Jan 2013 03:31:54 -0800

hi, I intend to bank two batteries in my rv in parrelel to increase stored ampage.. i have a 110 ah deep cycle and a 80 ah normal cycle , can these be banked together? thank you

By: Brian

Brian — Thu, 24 Jan 2013 18:56:02 -0800

Could the overheating battery on the new Boeing 787 Dreamliner be a simple case of incorrect wiring configuration. I know it might seem so simple it‘s stupid. But I cant help but feel it could be over looked. Just my 2 cents.

By: Gpeg

Gpeg — Thu, 24 Jan 2013 18:19:00 -0800

Hi again, I see from the series/parallel diagram that you show connecting batteries that are in parallel with each other, to another pair of batteries (in parallel as well) using a series connection. Is it possible to take two banks that are connected in series, and connect them to each other in parallel? Where would you connect the leads in that case? thanks again for your help

By: Mark

Mark — Wed, 23 Jan 2013 13:23:33 -0800

I have a light that runs off of a 12v car battery and draws 1 amp that I use for fishing. However, carrying a 12v car battery around isn‘t the most convenient. Could I hook two 6v lantern batteries in series to make a 12v system that would run the light? And if so, any idea approximately how long I could run the light for?

By: Sandy

Sandy — Mon, 21 Jan 2013 19:06:54 -0800

My wife and I are looking at building an off-grid house in the mountains (solar, wind, and generator). We were discussing our battery bank options with a friend, who recommended 24 2V batteries. Another friend recommended two banks of 8 6V batteries. Which one sounds better?

By: Kenny

Kenny — Sun, 20 Jan 2013 18:22:30 -0800

I am trying to figure out which was is better for running a popup camper the longest ( i know you cant be exact without knowing how much is running), by wiring 2 6 volt golf cart batteries together to make the 12 volts or 2 12 volt deep cell batteries for the more amps? i also have and want to use a 45 watt ( and poss buying more) solar charger. which way is better

By: Richard

Richard — Sat, 19 Jan 2013 08:05:58 -0800

Hello, I have a 24V bank consisting of 12 Trojan T105\‘s. After about 4 years one or more of the 6V batteries will come up with a bad cell.I understand that it is not practical to replace a singe battery, but it drives me crazy to replace the entire bank when some of the batteries appear to be just fine. I am thinking of going to a single string of 12, 2V batteries this time. My thinking is that I will then be able to replace an individual 2V battery because nothing will be in parallel. Does this make sense?

By: Dave

Dave — Fri, 18 Jan 2013 19:20:13 -0800

hi there, i\‘ve been toying with the idea of making a portable power pack for a 12V system main use for an airconditioning unit. Is this scenario possible? if not what would the problems be… a 12V battery, an Air Con compressor and a high output alternator/generator, all running off one fan belt. what are the tech specs needed for alt and motor? i.e. is it possible to charge a battery while drawing power from it??. 12v motors are becoming efficient and alternators are becoming more high capacity ie 110amps etc. is it possible? even doubling up alternators, example running 2 at 220amps of the same driven motor?

By: Terry

Terry — Fri, 18 Jan 2013 06:08:48 -0800

I have an EV that uses six 12v AGM batteries in series to provide 72 volts to operate the vehicle. If I hook up a 30amp stereo system across one of the 12 volt batteries, would it work? Would there be any negative electronic repercussions? Is there a better way to do this?
Thanks for any Help!

By: daniel

daniel — Thu, 17 Jan 2013 14:03:51 -0800

Ok i was just wonderin i have 4 12 volt 800 amp batteris ran in parallel and in series so added up toghter it us 24 volt and 1600 amps right? And i was just wondering if a stock alternator that is 12 volt would charge them and where would i hook it up..

By: gm

gm — Tue, 15 Jan 2013 10:48:18 -0800

What will happen if I connect 12v 18 amp paralell with 12v 30 amp ?

By: richard Hodgson

richard Hodgson — Tue, 15 Jan 2013 10:09:29 -0800

i want to charge a 18v Dc NiCd power drill battery using two 12v DC 100 AH lead acid batteries connected in parallel and which are charged using 12v solar panels. How can this be done. If I temporarily re-connect the two 12 volt batteries in series to get an output of 24v, is this too high a voltage to be connected direct to the 18v NiCd battery terminals to charge it satisfactorily.

By: ibnu mulkan

ibnu mulkan — Mon, 14 Jan 2013 19:42:14 -0800

i have a winston battery from china, in the brochure i found that the battery have operation voltage with charge is 4Volt and discharge is 2.8 volt.. what mean of that? second is how i configure this battery to get 12Volt ,, what voltage do i choose?(4Volt or 2.8Volt)
Thanks

By: Gary

Gary — Sun, 13 Jan 2013 15:39:43 -0800

I\\\‘m looking for some recommendations for setting up a small camper on solar. I have two 260w panels for 24v and a MS 45w mppt charge controller which will work for charging 12, 24, 48v batteries. The camper will be placed off grid in SoCal where the sun is good. What battery configuration will give me the best performance with these panels? Will be running rv fridge on 110 and a few cfl lights, laptop, led tv, dvd player. The trailer currently has two 6 volt batteries connected to a progressive dynamics 9200 controller that is more than adequate for the 12 volt system already on board when charged by shore power. So the idea is to have a solar system set up as a separate solar generator an a small seperate trailer that I can plug the camper into since I will not have shore power. Hoping to keep the 110v stuff working when needed and charge the on board 12v system. Also need to consider a PSW inverter. Any ideas on this set up?

By: Matthew

Matthew — Thu, 10 Jan 2013 18:03:59 -0800

i have a boat with a two bank system. the “starting” bank is a group 27 deep cycle wet cell battery, the “house” bank is 2, group 31 batteries wired in parallel. would there be any reason why i can‘t get the “house” bank to charge up fully? i have them all hooked up to a 20Amp marine charger.

By: john

john — Tue, 08 Jan 2013 16:09:13 -0800

I have an electric bike that has 3 12 volt 7 amp batteries and range is an issue. I want to buy 3 12 volt 12 amp batteries for a total of 6 in all, hook them up parallel to keep my 36 volt current. my goal is to extend the range of the motor and bike. Can I use to the two sets of battery\‘s together or should I mix them or what? Also how would it impact my amp rating?

By: justin

justin — Mon, 07 Jan 2013 17:12:22 -0800

I want to hook up 6 12v batteries and make them come out 48v how do i do that

By: Gpeg

Gpeg — Mon, 31 Dec 2012 21:30:35 -0800

Hi, great service you are providing here. I have an EV with a 72 volt system comprised of 6 12 volt 100 AH deep cycle batteries wired in series. Is there any advantage to changing the wiring from series only to the combination you suggest? What would my theoretical AH rating become? Thanks, and Happy New Year

By: John

John — Sun, 30 Dec 2012 20:23:08 -0800

I made a survival power cart this past year, and I am glad I had it for Hurricane Sandy. Here is my parts list:
-Plastic 3 shelf cart from Costco 99.00
-3 125AH 12v deep cycle marine batteries from Walmart 250.00
-1 Ramsond Sunray 3000, 12v pure sine wave inverter built in meter 500.00
-2 Anderson connector sets for 4/0 wire 40.00
-1 Heavy duty marine battery switch, internal sealed contacts 40.00
-30\’ of 4/0 xflex cable and lugs 250.00
-1 heavy duty 200A fuse 60.00
I keep the batteries float charged until they are needed. When the power goes out, I plug into the inverter and put the battery switch to on and I am up and running. I used the kill-a-watt meter to check all of my essential needs. Sump pump 500w, refrig 135w, hot water baseboard heat 150w, small tv and satellite box 100w, internet modem and router 80w, 60w CFFL bulbs 13w each. Before I see the volt meter on the inverter start to drop (the inverter shuts off at 10.5v)I plug the battery bank into my Chevy Tahoe that has a 8\’ set of 4/0 cables attached to my battery with a Anderson connector on it. When the Tahoe runs it charges the batteries and powers what I need. During Hurricane Sandy, most gas stations didn\‘t have power so I kept the Tahoe topped off with 5 gal gas cans I filled before the storm which carried me through 4 days until our power was restored. I was able to turn the vehicle on and off every few hours so it did not have to run continiously. I am planning to add 3 more 125A 12v batteries to my setup for longer runtime. This setup is quiet and when the Tahoe runs you cannot hear it in the house. My question is: Would I just need a 250W solar panel with a MPPT charger to charge my batteries if they were depleted to 10.5v and still have some power to run some of my \“needs\”?
If you want to see my setup, go to www.1pcmedic.com/powercart (give me a few minutes to post the photos)

By: sshresth01

sshresth01 — Thu, 27 Dec 2012 08:46:11 -0800

Is it possible to connect 100 Ah battery with 80 Ah battery in parallel both with 12 V? However, the batteries are of different companies?

By: eb

eb — Tue, 25 Dec 2012 12:05:55 -0800

I have a single 12V powertron flooded battery on my sailboat connected to a 15W sunforce solar panel protected by a sunsaver 10 Ah 12volt controller

This system powers an anchor light and bilge pump directly connected to the battery. It also serves to crank start a 9.9 outboard but this remains disconnected unless in use.

Here is m problem, after several weeks of use, and not being checked on …the anchor light goes out and when checked, the battery has less than 2 volts per the mulitmeter.

This is my second battery that this has happened with. the first one was with the 7amp sunforce controller that fialed so I bought the sunsaver and a new battery. now the battery is shot but the controller is still in good shape.

this has me stumped and could really use some help

merry Christmas

By: Michael

Michael — Mon, 24 Dec 2012 00:40:50 -0800

Great article. I converted my diesel vehicle from 24v to 12v but have been running through 12v starters because they are not powerful enough to start the engine. I would like to install a 24v starter without having to replace all of the lights, accessories, and other components. Could I run two batteries in series to run the 24v starter while connecting the 12v lights and accessories to one of the batteries and using a battery isolator to charge both batteries from the 12v alternator? If this configuration won‘t work is there another that might?

By: Ahmadi

Ahmadi — Wed, 19 Dec 2012 03:27:34 -0800

Hello,
I am in Afghanistan and want to make a 2 or a 5 KW AC power from battery bank.
the solar panel which i can find here are 160W panels and 70amps up to 150amps battery, and my inverter (dc to ac) is need 12V DC.

So can you tell me how to wire batteries and how many solar panels and so on. please.. thanks

By: Brett

Brett — Tue, 18 Dec 2012 12:35:47 -0800

I have a truck camper and I want to wire a deep cycle marine battery to be run in parallel with the truck battery in order for the furnace to last longer on cold nights. Is this a bad idea?

By: Matthew

Matthew — Mon, 17 Dec 2012 21:02:43 -0800

What happens if you want to wire a couple hundred or maybe thousands of lithium batteries (AA sized) to each other to get 24 volts and around 275 amps?

By: musthafa

musthafa — Mon, 17 Dec 2012 19:50:11 -0800

If i connected 12v/50a battery with 3v/800ma, what is the output voltage and current?

By: Arun

Arun — Thu, 13 Dec 2012 00:31:47 -0800

I have 2 questions:
1. Is connecting two sets of battery banks in series-parallel connection just a theoretical approach or there are some limitations?

2. What happens if 4 batteries of variable ratings are joined in series parallel? I mean (1st battery)1V,1Ah +ve terminal of which is serially connected with negative terminal of (2nd battery)4V,4Ah which are in parallel to (2nd row 1st battery)2v, 2Ah +ve terminal of which is serially connected with negative terminal of (2nd row 2nd battery)3V,3Ah batteries.
Does the 4V, 4Ah one back flow to 1V,1Ah directly or it will go through 3V and 2V ones first? And can we predict that the resultant output will be 5V,5Ah???

By: Ricky

Ricky — Tue, 04 Dec 2012 21:29:08 -0800

what is the benefit of running two 6 volts batteries at 110 amp hrs. in series instead of buying one 12 volt battery at 110 amp hours. You will just be spending more money on buying 2 batteries.

By: Hugh

Hugh — Tue, 04 Dec 2012 16:17:44 -0800

I\‘ve got 8 six volt batts in series to power a 48 volt inverter. I have a standby inverter I want to attach to the same bank…however, it requires a 24 volt input. Can I tap the 48 volt bank for 24 volts by cross-tying the first four in series (24 volts) withe the second 24 volt half. The series would remain through all 8 batts for the 48 volts and I would get a balanced 24 volts off the two sets of 4 batts hooked in series and tied parallel at the 24 volt stage….what do you think?

By: Dennis

Dennis — Sun, 02 Dec 2012 07:22:19 -0800

I\\\‘m replacing my batteries in my motorhome which had three 12v batteries. I purchased four 6v 230AH batteries if I connect these series/parallel can I come off from this for my main battery or should I use another 12v crank battery for my main battery?

By: Rick

Rick — Thu, 29 Nov 2012 20:34:20 -0800

Hi, I have twelve 6 volt 225ah golf cart batteries and need to set it up as 24v bank for my inverter. What\\\‘s the best way to wire this? Thank you!

By: John D.

John D. — Wed, 28 Nov 2012 14:36:40 -0800

I have a bunch of questions:

If I am going to connect a number of 12V batteries in parallel, do I have to worry about the batteries being slightly different models or brands? What about different amp-hour ratings?

Can a bank of two 200Ah batteries be expanded with two more 230Ah batteries? Or do they have to match as exactly as possible?

By: Robert

Robert — Thu, 22 Nov 2012 12:57:42 -0800

Hello, I‘m creating a 48volt solar system with 4 each 12volt deep cycle batteries (all the same aH). My question is, will my Solar array need to push out 50 plus volts to charge the battery bank or will the MMPT take care of this even if the array only delivers less than 48 volts?

By: david

david — Wed, 21 Nov 2012 23:25:08 -0800

understood, but can i hypothetically only add one 2v cell in parallel with one of the current 2v cells in the original bank to increase the capacity with that new cell?

By: david

david — Wed, 21 Nov 2012 03:26:30 -0800

i have a solar charging system with 24 X 2v cells in series to create a 48v feed to the victron unit. can i ad on more cells in parallel to some of the current cells to increase capacity but keep the 48 v intact?

By: Ravindra

Ravindra — Tue, 20 Nov 2012 08:48:39 -0800

how to connect two batteries so that I can get twice of backup of a single battery also the voltage and current should be the same as that of a single battery means I just want to double the backup nothing else.

By: A.S.C.

A.S.C. — Tue, 20 Nov 2012 08:44:13 -0800

All alien language to me. I need to know if what I want built is possible. Someone with more knowledge than me will be doing the building. I need a bank of batteries which can take a small/medium RV off the grid AND be charged with a diesel generator, solar panels, truck electrical system (when truck is in operation), or from an \‘on the grid\’ AC service. In addition, I would like to be able to hook in a solar generator to charge while the batteries are charging or charge from the batteries themselves. If something like this is possible, can it be carried safely in the bed of a super-duty pick up which also carries a dual gasoline/diesel transfer tank?

By: Collin

Collin — Sun, 18 Nov 2012 20:52:27 -0800

If you are running the four 6v batteries for the 12v output can you charge all four battery with one 12v charger? If yes ..do I put 1 positive lead on the front row battery set and the negative lead on the back row set?

By: Steve Heemsoth

Steve Heemsoth — Sun, 18 Nov 2012 09:45:50 -0800

If I hook two 12V batteries in Parallel, I know that the CCA will increase. My question is: will this hurt any part of the electrical system to operate the vehicle this way with more amps running through it?

By: nunyafb

nunyafb — Wed, 14 Nov 2012 22:53:30 -0800

Hi i have 16 6 volt 125 amp/h hooked up as4 banks in series and the 4×4 in parallel but was told serpentine pattern is better which is how i have 6×6 traction batteries hooked up in that way but cant get my head around how to do it with these 6 volt batteries thank you

By: T.J

T.J — Fri, 09 Nov 2012 10:41:51 -0800

all the articles are interesting but my question is wich is the best configaration for a 24 volt sola system 12×2volt batteries in parallel or 12×6volt in series & parallel both have the same potential amp hours hope to get a reply T.J

By: dave d

dave d — Thu, 01 Nov 2012 06:29:44 -0700

I bought 2 thunderbolt 45 watt solar systems from harbor freight, along with 3 of their 35ah batteries. I want to use the system to recharge my laptop, rechargeable batteries (AA), walkie talkies, etc. I have an inverter to convert to AC. Should I connect the batteries in parallel to maintain 12 volt but increase AH\\\\\\\‘s?

By: Krishna

Krishna — Wed, 31 Oct 2012 23:38:12 -0700

I have UPS setup to which I have connected two battery banks of different ages in parallel. Each bank has 16 batteries connected in series .

Bank 1 : one year old
Bank 2 : purchased recently(less than 2 weeks old).
All batteries are 12V , 26 AH and same company make, except the age.

Initially with just just battery bank one I use to get backup time of 70minutes, with addition of second bank its hardly increased to 120min and sometimes its even less…

I had a feeling that the second battery bank(newer one) is not being completely charged due to the first battery bank connected in parallel.

Can you suggest me how to isolate the two battery banks during charging.

By: greentech

greentech — Mon, 29 Oct 2012 08:58:25 -0700

I have a variety of 12V batteries with different AmpHour capacities. I also have a solar/wind setup to charge them all with seperate charge controllers. I have setup a bus bar for them all to connect to. What I want to know, is can I have multiple groups of batteries of the same type/capacity together in parallel to the bus bar without causing a rapid drain from the banks with a much larger capacity than the other banks?

i.e. I have 2 high capacity banks and want to be able to remove 1 bank, as well as charge multiple small capacity batteries for mobile use. Here is the typical setup ->

Bank 1 – 3 AGM 180Ah batteries
Bank 2 – 2 Gel 105Ah batteries – periodically removed
Bank 3 – 1 Gel 15Ah battery – charged, then removed
Bank 4 – 1 Gel 7.5Ah battery – charged, then removed

All of these are then connected to the bus bar simultaneously.

Will this be ok, will I need diodes?

By: Mike

Mike — Sat, 27 Oct 2012 15:17:05 -0700

Charging 12/24V system? we have a total of 6 identical 12V batteries, paralleled in banks of 3 equalling two 12V sources and we have them in series only for the purpose of charging them with a 24V solar panel that we had on hand. Is this a sufficient charging method given that that 12V banks serve different loads and have different discharge rates? or do we need to order some 12V solar panels?

By: john

john — Thu, 25 Oct 2012 23:38:56 -0700

i have begun compiling the componants for an electric vehicle. it is to be a 144 volt system. i have 12, 12 volt deep cycle sealed agm batteries that are aprox 140 amp hrs. ea. ( they weigh 100 lbs. ea.! ) i also have purchased; ( something that i have not seen ANYWHERE, as has no one else that i know.! ) weird. it is a battery charger made for a motor pool 12 volt vehicle charging. it has 12 individual, + & – cables to treat each battery individually in the pack. it monitors them in groups of 2. charging 14, floating 2 upon full charge. my question is this: can i build a solar array that will operate this charger? i have a 12volt to 120 volt 1000 watt digital inverter and a solar controll modual…wondering.

By: Lee

Lee — Tue, 23 Oct 2012 07:17:46 -0700

I have a 24 volt battery bank with a wind turbine,but I want to use a 12 volt power inverter.What would I need to do so the feed to the inverter is stepped down to 12 volts? I found your tread very informative

By: Gautam Patel

Gautam Patel — Tue, 16 Oct 2012 03:33:07 -0700

I have Manlifter with eight number of batteries 6V,375Ah,Now one battery was not charged and I want to replaced by only one now battery out of eight batteries.Kindly be advice me is it possible to replace only one battery from battery bank.

By: MuNa

MuNa — Mon, 15 Oct 2012 09:52:07 -0700

Shall I use 20ah battery instead of 8 ah battery in pc ups?

By: geoff

geoff — Sun, 07 Oct 2012 12:57:47 -0700

Hi,

I am wondering if I can use a 12 V alternator to charge a 48 V battery bank. Could the 12 V alternator connect to a step-up transformer to do this? Assuming it could, would the alternator\‘s output then drop by an quivalent ratio? i.e. if I step up voltage 4X, do I step down amperage 4X?

By: tc

tc — Wed, 03 Oct 2012 08:40:11 -0700

I am helping a friend with a problem. He set a solar charging system for 3 12v 690amp deep cycle batteries from Kragen. They are hooked parallel. He has 6 15 watt harbor freight solar panels parallel. Then it runs to a inverter to power a 115v .9amp pump

He told me that he is getting 20volts going to 3 batteries, the batteries still show about 11.8.

So it sounds like the batteries aren‘t fully charging.
Any ideas?

By: tc

tc — Tue, 02 Oct 2012 21:39:29 -0700

If I hook 3 12v batteries in parallel is it a good idea to tie feed from the negative on battery #1 and the positive on #3?

By: JD

JD — Mon, 01 Oct 2012 13:37:00 -0700

can i connect 8 batteries in series parallel for 12v? in says in diagram that any number should be possible but wanted to ask the tech to double chech.

i have a hydro wheel that produces 25amps @ 12v. my expanded battery bank is now going to be huge with 8 L16 6v 600ah batteries. even though input is constant we do draw the system to 60% at least weekly through heavy use of air heater/power tools/laundry. is series/parrallel the optimum setup for this type of deep cycling? we have a very nice new tristar morningstar charge/diverson control.

By: Gordon

Gordon — Mon, 01 Oct 2012 12:38:07 -0700

I have a 24 volt solar system, can I hook up two 6 volt and one 12 volt to get the 24? Two batteries are Trojan and the 12 volt is a gel battery.

By: Sandor Szabo

Sandor Szabo — Fri, 28 Sep 2012 02:16:15 -0700

Hi,
Congratulations for this site!
I use 6 cell 2300 mAh LiFe battery packs with cells connected serial to get 21,6 V. I use 2 pcs of such packs in parallel to get 4600 mAh with the same voltage.
Recently I have noticed that one of the pack discharges more than the other and it also warms up significantly, while the other one has a normal working temperature and it discharges unusally less.
I drive an RC helicopter with them. Normally with 5,5 minute flying time both packs charges about 1400 mAh, and now the hot one gets 2000 mAh, the colder only 1000 mAh. Normally both packs discharges 1500 mAh.
My questions are: Which pack has a bad cell? The one which is overheated and discharges deeply or the one which does not have high temperature and discharges less then normally.
Thank you.

By: jodey

jodey — Thu, 27 Sep 2012 19:05:10 -0700

i have a -1.5v, and a -4.5v, and a -9v battery. i need to add these 2 different ways to equal -4.5v. help me please?

By: Chris

Chris — Sat, 22 Sep 2012 23:25:59 -0700

I am wiring two 12v marine deep cycle batteries in series to provide 24v to some high powered LED lights on a boat. Two questions; (1) will I experience any problems using one group 24 battery and one group 27. (2) If the two batteries are wired in series, is there a way to make a connection to just one of the batteries to supply 12v to a second load? If so, how? Thank you!

By: dean

dean — Sat, 22 Sep 2012 18:33:35 -0700

I was wondering since I have 4 deep cycle RV batteries connected in parallel where do i hook up the battery charger clamps..can i put them on one battery or do they need to be on two seperate batteries…

By: Dante

Dante — Wed, 29 Aug 2012 10:42:23 -0700

Hi, can i connect a battery to my car ( in parallel ) while i‘m driving,and recharge my battery?

By: kelvin

kelvin — Sat, 25 Aug 2012 19:09:55 -0700

I have a 48v Inverter powered by 4, 200 ah deepcycle batteries of 12v each. The batteries are connected in series. I am not a technical person but i am looking for a way of having more hours on the inverter by using a parallel connection. If i buy a 12v inverter and use a parallel connection can i achieve that? What are the implications? Will i have to reduce the number of appliances on the Inverter because the volts will drop from 48 to 12?

By: Jesse

Jesse — Tue, 14 Aug 2012 20:57:33 -0700

I thought if you hooked up 4-6 volt/10 AH batteries in series parallel, you would end up with 24 volts and 20 AH, not 12 volts and 20 AH?

I need to design a battery system for a marine gas turbine project, it will run 12 volt accessories and need 24 volt only for the start cycle which will be considerable at about 500 amps for 30 seconds, what do you reccommend? 2-12 volts or 4 6 volts?

I would like to run a 12 volt alternator and how would I hook it up to insure both batteries will be charged equally?

Thanks

By: ja.robby

ja.robby — Sun, 29 Jul 2012 09:53:41 -0700

how do i connect four 6volts 225ah batteries so that
i can get 24volts with or without increasing the ah.

By: jarobby

jarobby — Sun, 29 Jul 2012 09:33:59 -0700

These are very good and important information i like it.

By: Bob T

Bob T — Tue, 24 Jul 2012 16:46:08 -0700

I installed 4 new Batteries, initial charge looked good, it now appears one or more Batteries do not maintain charge and keep drawing current at rest,
How do I find the faulty Battery?

By: Jim Mitchell

Jim Mitchell — Thu, 28 Jun 2012 14:11:24 -0700

I have just purchase a boat that has 12 6volt batteries for the \\\“house\\\”. Does this setup seem connected right? There are 2 rows of batteries 6 in each. In the first row all + are connected together and all the – are connected to the + in the other row. Which leaves all the – in the second row connected together.

By: Mike

Mike — Sun, 17 Jun 2012 13:38:54 -0700

I have a new RV that uses 4 6 volt batteries in series – parallel to provide the 12 volts to various systems on the coach including an inverter for the house hold refrigerator. My query concerns the proper battery tender for this set-up. What tender set-up should be used during periods of RV storage so that the batteries remain charged and do not sulphate?

By: Will

Will — Mon, 11 Jun 2012 06:54:08 -0700

Currently have two identical LiFE batteries wired in series to power a small transmitter. On the same rig are servos that can run happily off the voltage of one of the batteries, and draw very little current. Would it be dangerous to run a cable in parallel off of the jumper cable connecting the batteries together? It seems like it could lead to a slight voltage imbalance between the two batteries, how significant is that?

By: Mark

Mark — Thu, 07 Jun 2012 06:54:24 -0700

Is it possible to connect 5 batterys in parallel and the make a series connection to a bank of one battery just to increase the voltage? For example, if I have 6 6V 220ah batterys and want to create a 12V 1100ah bank.

By: john

john — Wed, 29 Feb 2012 21:05:43 -0800

now I‘ll connect my friend hydraulics