How much acid/water in a battery?

[Bob McCarty]

This cub came with a new, but dry 6V battery. I'm pretty sure the acid to water ratio is 2:1. Napa sells quart and gallon bottles of sulfuric acid. Is a quart enough to dilute and fill the battery? Will it need to be charged prior to use?

[Don McCombs]

Why mess with measuring and mixing? Use a pre-mixed fluid.

https://www.autozone.com/batteries-star ... /66445_0_0

[Crimson Tim]

If you do mix, remember, mixing acid and water is highly exothermic. Slowly pour acid into water only. Take it slow and give time for heat to dissipate if necessary.

Do not pour water into acid, as it can get violent!

[Bob McCarty]

Why mess with measuring and mixing? Use a pre-mixed fluid.

I couldn't tell from the Napa picture if it was premixed or not, but is a quart enough or is that amount to top off a low battery?

[Don McCombs]

It doesn’t take anywhere near a quart to top off a low battery. Plus you top it off with plain distilled water. I would start with a quart and see where it gets you. And, yes, you need to charge it.

[Bob McCarty]

Don, I'm confused. If it's premixed why do I need to add distilled water?

[Don McCombs]

In use, the hydrogen and oxygen in the water will gasify and leave the battery, leaving the sulfuric acid behind. This will increase the concentration of the acid in the fluid. Replacing the H and O will bring the pH back to the proper level.

[Bob McCarty]

This battery was new and never had any acid/water in it. That's why I was asking about volume.

[tmays]

When I’ve bought atv batteries, if I remember correctly, the battery gets filled and sits idle for 24 hours then gets charged. Can’t help you with the volume

[Eugene]

I was asking about volume.

Fill to just cover the plates - no more than just covering the plates. Wait 24 hours then charge. Charged, fill just to the opening/fluid level indicator in the bottom of the cap well.

[Gary Dotson]

Bob, I think it will take more than 1 quart, get 2 and if you don’t have to open the 2nd one, just return it. I filled a lot of batteries, back in the old days, be incredibly careful with that stuff, acid resistant gloves and good facial protection. Don’t hurry the job!

[Cubfriend]

Be very careful not to spark near the battery when there are hydrogen-sulfide gases present. Hook up charger to battery before plugging charger in to wall outlet. I’m sure you know this but don’t want anyone to be hurt just in case. Unplug charger before removing leads from battery.