Liquid on top of car battery

So, I recently filled my battery with distilled water. Unfortunately, I’m fairly sure I overfilled it. I filled it, capped the little fill port, and wiped the battery clean and dry. Then because the indicator said I should, I went and got a battery charger. When I got back and opened the hood, there was clear liquid, I’m assuming just overflowing distilled water because this is a gel battery …

Should I try to draw out some of the water? Did I ruin my battery? Should I charge it? I don’t want any explosions, I’d make a terrible TwoFace.


  1. What brand of battery is it?
  2. It’s a gel battery, right? Why add water? Is this suggested by the manf’r?
  3. What does the manf’r say about adding water? Isn’t there some sort of indicator to show ‘full’?
  4. Be very careful handling this ‘liquid’. If it was added as recommended, it is now an electrolyte, and possibly highly acidic. Do not consider drawing out some ‘water’. It is no longer water, but an acid solution.

I have yet to meet a gel cell you can add water to, what battery do you have?

This should be good…

Yeah, I was misinformed about the gel batteries, it’s a maintenance free flooded battery. I had a little trouble reading the label, but it looks like it’s an FB 3BBL (S) - MF. There is a little view port that has a color coded indicator, and it said it needed distilled water; now it says it needs charged.

I know I overfilled it but I don’t know what to do about that. I see now that there is liquid pooled in the bottom of the harness, too. So if I’m leaking the electrolyte, what do I do? Is it even safe to drive?

If you look down those fill holes you’ll see they’re not just plain holes.
There’s plastic tubes that extend down 1/2" or so. They’re to keep the electrolyte from wicking up.
If the electrolyte reaches those tubes it will creep up and out for sure.
Sulfuric acid has a strong urge to travel.

Get a small turkey baster and carefully draw out just enough liquid to bring it below the fill tubes.
Use goggles and carefully discard the acid in a pail of water.

Won’t that change the specific gravity of the electrolyte? Doesn’t it need to be adjusted?

The specific gravity of the electrolyte has already been lowered by your addition of distilled water. You cannot restore it, unless by adding more concentrated sulfuric acid. For now you are merely trying to adjust to a proper amount to avoid spills and overflow. Then you will charge the battery and hope for the best. Yes, it is safe to drive.

You guys are awesome, thanks for your help. Now I have to find a turkey baster …

You could also use a syringe or small hose and siphon bulb.

The battery is full when the water touches the lower ends of the plastic fingers, when that happens the water curves from surface tension instead of remaining flat surfaced.

“The battery is full when the water touches the lower ends of the plastic fingers”

The battery is overfilled at that point.

The extra liquid and change in concentration of electrolyte is probably not enough to cause any significant change in the battery’s performance. But it will continue to seep until it blows out all that extra liquid, which can corrode the heck out of your battery tray, wiring, and anything else that it touches that isn’t plastic. I’d try to get the extra liquid out too. (make sure you wear goggles and protective gloves, and don’t reuse the turkey baster for food)

The problem will only worsen as the weather warms up and the battery gets hotter if you don’t.