Battery boiled over on 1/2 amp?

[MuskieJunkie]

So here's what I know. I bought a used boat with a newish starter battery, it worked perfectly but was low on water so I topped it off, this off season I hooked it to an automatic 500 milli amp vexilar type of charger. After about 2 days the battery had boiled over.

I didn't think that was possible with a automatic charger. Is the battery done? Is the charger bad (it's new)? Did I over fill the battery?

I think I might be sticking to Optima batteries from now on. Thanks for the help.

[Macgyver55]

When you say "topped it off", how full did you go? Typically batteries need some air space left in the top for the gasses to escape to when charging. As long as the plates are all covered with water the battery is good to go, but if you filled it up to close to the caps it will push the water out.

[BobT]

Most batteries, even new ones, will never charge to the point of becoming an open circuit. In other words, they will always draw some current from a charger. For this reason, it is possible to fool a charger into thinking a battery still needs to be charged and not automatically stop when using the low amp trickle charge setting. I don't like to leave a battery connected to the low amp charge setting unless I am checking on it from time to time for this reason. I have seen too often that my batteries have dehydrated because the charger continued even after the battery was fully charged.

[Tom7227]

Brian - to answer your question - no you probably didn't total the battery. Hook something up to it and see if it works. If it does then wait until spring and give it another charge, put it into the boat and see what happens. Clean up any spilled acid by pouring baking soda on it and letting it get neutralized.

If you want to learn a lot about batteries google "CAR AND DEEP CYCLE BATTERY FAQ 2009" and the name "Darden" and you'll get a decent site that explains a lot.

[BobT]

Good advice less one thing. I wouldn't just wait 'till spring. Top off your battery to specified level using distilled water, charge it up, and check it from time to time until spring. Just avoid over-charging as this is what causes the fluid to evaporate.

[jeffreyd]

and it might be good to do a deep discharge on it and bring it back from ground up. as noted above, there are slots in the holes and the water should be to the bottom of the shoulder where the slot starts. also you should take the caps off when charging to allow gas to escape. make sure you clean up the spill quickly use baking soda or commerical cleaner for battery acid.

[PierBridge]

Yes you over filled it and I'd bet the battery is just fine.

[MuskieJunkie]

When you say "topped it off", how full did you go?

FULL

I didn't see anything that indicated a fill line so I put in as much as it would take. Sounds like I over filled it. Thanks for the info guys.

[Pat K]

The bottom of the tube with the slots in it is the full line. Even if the fluid didn't boil it still expands as the battery is charged.

The slots are to vent off hydrogen gas created when charging.

[Whoaru99]

Yeah, the bottom of the extension in the filler hole is the full level. Probably about an inch, give or take, below the top of the battery.