Comments on: When Should I Add Extra Sulfuric Acid to my Battery?

By: matt

matt — Fri, 27 Dec 2024 09:54:59 -0800

I purchased a used forklift with a large 36V battery, 18 cells. It had clearly been overfilled and boiled over repeatedly, as was evident by loads of corrosion on, around, and underneath the battery. Battery would only charge to ~70%, which dropped quickly and lasted only a few hours of use. I have a background in chemistry, so felt comfortable trying to revive it by adding acid. I removed the battery, cleaned up all the corrosion, washed everything thoroughly, and neutralized with baking soda solution. I Measured specific gravity of each cell to find they were on average ~25% sulfuric acid, far short of the factory spec of 33.93%. There was not visible evidence of sulfation as far as I could tell, so my assumption was that most/all of the loss was from repeated boil overs due to over filling. I added 96% sulfuric acid in varying amounts to each cell, based on specific gravity. Being cautious, I added about 1/3 of what I calculated was needed to bring up to factory levels. Ran a few battery cycles and saw significant improvement, so I repeated this process again. Cells are now all ~32% sulfuric acid, battery charges to 100%, and is good for many days of use. Should I continue with my final addition to get that last ~2% increase to factory spec, or quit now, as the battery is working quite well? My concern is the possibility that there was some sulfation contributing to the low SG, and I risk that breaking free, going back into solution, and having too high of a concentration.

By: Cassidy

Cassidy — Sun, 25 Aug 2024 04:11:53 -0700

Thank you for the information

By: Clinton Sharp

Clinton Sharp — Thu, 08 Aug 2024 15:28:53 -0700

I have a very large, 2 year old (or less) battery that sat for about 6-8 months. It would only charge to 5v so I checked cells and ended up adding about 1/2 gallon of distilled water to get the levels right. It charges to 6v now. Is there anything else I could add to help it? Most expensive battery I've ever bought so I'm crossing fingers. Also, should i take it out and shake/ mix it? Thanks

By: Liebardt Tjiuongua

Liebardt Tjiuongua — Fri, 05 Apr 2024 06:55:08 -0700

I put distilled water in my 722 Willard battery now it is not charging.must I reduce the water level.

By: Pio

Pio — Thu, 07 Dec 2023 21:46:39 -0800

I added battery acid to my battery when the battery water levels had gone low am l in trouble now or we'll see the effects in a prolonged period of time

By: Alinanye Patrick

Alinanye Patrick — Sat, 11 Feb 2023 22:34:25 -0800

Is it right to refill drained cells with chloride exide?

By: Eric

Eric — Sat, 23 May 2020 06:26:34 -0700

With an emptied battery ready to fill acid will i need battery water to top up or it's acid to the maximum mark?

By: always choosing wrongly

always choosing wrongly — Wed, 18 May 2016 23:00:23 -0700

Please help…my friend put salt and water in my less than 2 year old battery whi h continuously needed a jump start. Battery water seemed to boil and bubble whenmuxture was added along withcharger. Battery responded well i think to charger, although it is not fully charged because we had to remove it due to bad lightning storm. Battery turned super hot to the touch!!!is battery now totally destroyed now? Xar starts and runs but battery is HOT!!! Will battery blow up? Will battery now mess up cars computer? What can i do now????!!!

By: Ninja Kev

Ninja Kev — Tue, 25 Nov 2014 13:22:34 -0800

You answered my question and I’m glad I checked with you first! Thanks alot!

By: Justin

Justin — Sun, 05 Oct 2014 17:46:14 -0700

Of course you recommend it, I assume for liability purposes… However, can one empty, ensure all the cells are empty, and refill them with electrolyte’s? FYI, I bought this 5lb dirt bike battery ($65), sealed it… then the bike sat for a year. Today I noticed the batteries cells were completely dry/empty when I reopened it. Just buying a container of Electrolyte’s $8.
Thank you for your response. Disclaimer; I am responsible for any damage I may bring upon myself ;)
V/R Justin

By: Tech

Tech — Fri, 16 May 2014 14:18:54 -0700

It is impossible to do so accurately. We do not recommend adding anything other than distilled water.

By: vs

vs — Thu, 15 May 2014 05:57:33 -0700

what to do if some qty. acidic water spilled out? How to regain the quantity of acid that spilled out?