For reference this is what the CPAP machine says under the electrical version of the manual, and this is where I get a little confused (though I have had others tell me they use this battery and inverter with their cpap just fine – but they use a 3 panel 45 watt solar charger which is unfortunately out of my price range.):
AC power consumption (with 60w power supply) 100-240 VAC, 50/60 Hz, 2.1 A
Ac Power consumption (with 80w power supply) 100-240 VAC, 50/60 Hz, 2.0 A
DC Power consumption: 12 VDC, 6.67 A

Any help or explanations are appreciated, as I am brand new to trying to figure this stuff out. :)

Thanks for your help.

Thanks

I have a newer sealed, maintenance free, mid-range (in terms of quality) standard AGM 12v deep-cycle Marine/RV battery

930 marine cranking amps, 145 minutes reserve capacity, 75 amp-hours.

This is my first experience with AGM batteries of any sort.

My question: Is the electrolyte, absorbed into the glass matting, in these AGM batteries subject to stratification in the same way that the electrolyte in a flooded wet battery is?

Reason I ask: I use a smart charger that incorporates 8 steps in the charging/maintenance cycle. The 1st step is an automatic desulfation step. The 6th step is an OPTIONAL step that can be used occasionally to “recondition” or destratify the electrolyte in flooded wet batteries. This is accomplished by the application of 15.8v, for short periods of time depending on the voltage of the battery, to induce out-gassing and turbulence due to the rising bubbles. Destratification occurs when the turbulence causes the electrolyte to be mixed and rendering the SG uniform throughout the depth of the cell.

My obvious next question: Will it ever be necessary, or even safe, to use this optional 6th “reconditioning” step when charging/maintaining this mid-range, deep-cycle AGM battery?

I’m using the battery for a trolling motor.

Thanks for your time!

Recommended Charging Information
Alternator: 13.65 to 15.0 volts
Battery Charger: 13.8 to 15.0 volts; 10 amps maximum; 6-12 hours approximate
Float Charge: 13.2 to 13.8 volts; 1 amp maximum; (indefinite time at lower voltages)
Rapid Recharge (Constant voltage charger): Maximum voltage 15.6 volts. No current limit as long as battery temperature remains below 125°F (51.7°C). Charge until current drops below 1 amp.
Cyclic or Series String Applications:: 14.7 volts. No current limit as long as battery temperature remains below 125°F (51.7°C). When current falls below 1 amp, finish with 3 amp constant current for 1 hour.
All limits must be strictly adhered to.

Performance Data
Cold Cranking Amps: 800
Cranking Amps: 1000
Nominal Voltage: 12 volts
Open Circuit Voltage (fully charged): 13.1 volts
Internal Resistance (fully charged): 0.0025 ohms
Capacity: 66 Ah (C/20)
Reserve Capacity: BCI: 140 minutes (25 amp discharge, 80°F (26.7°C), to 10.5 volts cut-off)

I am experimenting with a machine that runs on 24v. I want to replace the power supplies for a battery pack. I need about 100 Ah, so Im thinking 2 12v 120 Ah connected in series. My question is: Will a 24V/13A charger do the job on recharging my setup? I don’t have that much experience with batteries. I think it will, but rather ask the expert.

Thanks for your help

I suspect my inverter is sized with a greater capacity than my battery bank can safely support. But it\‘s what I have.

I would also love to be able to manually select the charging source for the house bank to switch between the engines\’ alternators or a solar array in addition to the generator. Everything is 12V.

Two questions: Do you see any holes in my plan, and for the charger is my best option to get as many amps as I can afford?

Thanks in advance!

What I am hoping to do is use a ready-made portable power pack to run a telescope and hiker\‘s GPS unit from a 12VDC cigarette-lighter style socket, a couple of USB powered items, and finally a laptop and possibly a little more from AC sockets provided on the same unit.

Expected consumption would be as follows:

Telescope (12VDC) ~0.7 amps for 5-12 hrs/night
GPS unit (12VDC – not sure, but probably very low draw and only for 5-10 min no more than 2x/night)
Laptop (110VAC) ~2.0 amps for 3-8 hrs/night
Cell phone (USB if available on power unit, AC adapter if not ~200mA not every cycle, but when needed ~2 hr recharge)
Tablet computer (AC adapter probably not used every time – 2000mA for 3-5 hrs when used)

Several places in your material and others I\‘ve read, the statement is made that one should get the highest Ah rating they can. I think these materials have been about higher and possibly shorter-term draw in all cases, but I\‘m not sure. Other material says, for the type of low power/long usage above, one should use something with an Ah rating of only about twice what they would probably use in one session on average, so as not to draw the battery down too much in one night, but enough of the total so the cycling is deep enough to preserve battery life by the proper amount of cycling (or something like that ;-). Still other places, I\‘ve read that it is better to draw down the battery less (5-10% of capacity) to increase the lifespan of the battery. All of this has me confused.

I am trying to figure out two last things before I can figure out what I need:

1.) Should I limit my choice of Ah rating to a lower number (twice my need per cycle) for my kind of usage?

2.) This may be outside your subject matter expertise, or depend on specific unit features, but I also need to know if built-in inverters draw power when nothing is plugged into them. I haven\‘t been able to find anything on that question.

Is my charger working properly? Or is it not really a smart charger?

Anyway – I plugged in between 4pm-6pm on day #1 day (at our lodging on normal electricity) to charge the batteries. By 5am THE NEXT MORNING…the batteries were STILL NOT FULLY CHARGED. Same thing happened on morning #2 and #3. The starting battery was was obviously fully charged each day; however, depending on the TM battery, one may have been about 90% charged; the other in it\‘s final stage (like 98%). The next day one TM battery was like 80% and the other 90%…after 12 hours on the juice. Brand new batteries on a brand new charger. I don\‘t get it!!

Optima \“recommends\” using 10A chargers on their blue top batteries (if not all their batteries). I\‘m considering moving to a 36V trolling motor. Here\‘s my question. I\‘m going to have to upgrade to a 4-bank charger to do this. I don\‘t want to trash two Optima batteries that I just bought. I also don\‘t want to wait 12-hours to have fully charged batteries. The charger I want to go to chargers at 30A, and I don\‘t think it has a regulator (Protournament 300 Quad). That said, will 30A charger HURT the Optima batteries?

10A is going to take 10-12 hours to recharge a depleted trolling motor battery…no biggie for non-tournament fishing…but when you need the boat ready to go 12 hours after you get out of it…12 hours to charge two 12V batteries ain\‘t cutting it. Had I known it was going to take 12-hours to get a full charge I wouldn\‘t have bought the Optima batteries. To hear my partner tell it, his Odyessy batteries are FAR SUPERIOR to Optima anyway.

This is a pretty sophisticated battery charger. I‘ve always just had simple ones but this one does far more. I‘m not even sure I understand all the functions and I‘m fairly techno-geeky.

More info: http://best-gear.org/la-crosse-technology-bc-700-alpha-power-battery-charger/

Thx,
Mike