Battery Boil - what came first?

[Tikvah]

I opened my battery door the other day and my engine start batteries were gurgling.  Also, the top of them were a bit wet. 
I haven't been driving for awhile, just parked and maintained on a battery charger.
I haven't seen that before, so I killed the disconnect switch and unplugged the battery charger and left it there a few days.
Tomorrow we start driving again, so today I opened the door again, unhooked and pulled the batteries and they were low on water.  I poured about 1-1/2 gallon into the two batteries.

So, did they boil because they were low on water?
Or, did are the low on water because they boiled?

Dave

[bobofthenorth]

Your charger boiled them dry.  You need a better charger if you want to leave it on all the time.

[Oonrahnjay]

I opened my battery door the other day and my engine start batteries were gurgling.  Also, the top of them were a bit wet. 
I haven't been driving for awhile, just parked and maintained on a battery charger.
I haven't seen that before, so I killed the disconnect switch and unplugged the battery charger and left it there a few days.
Tomorrow we start driving again, so today I opened the door again, unhooked and pulled the batteries and they were low on water.  I poured about 1-1/2 gallon into the two batteries.

So, did they boil because they were low on water?
Or, did are the low on water because they boiled?

Dave

    Hard to know without measuring voltages, etc. but it sounds to me like your charger has been overcharging them.  You need a higher voltage to get through the resistance of the battery when charging but when the battery is at (or very nearly at) full capacity, the charger should drop back to a lower "float" charge (assuming that you have a "smartcharger".   And batteries will react differently to charging depending on whether they're fresh and working well or older and showing signs of aging.
    On the other hand, wet-cell batteries lose a little water over time with normal charging.  When was the last time you checked water levels?
    All just WAIG'n, but that charge system is the first thing I'd look at.

[Tikvah]

When was the last time you checked water levels?

I made sure they were full, and clean the terminals at the end of summer when we left our park in Michigan.  Put on some miles since then but just normal stuff.
I have a small smart charger... but I've had that awhile.

Dave

[bevans6]

You may have one failed or failing cell in a battery.  The smart charger shifts into trickle charge/maintenance mode when it senses the voltage of the battery is up to a certain level and current flow has tailed off to near zero.  If a battery has a bad cell it might never get to that point, and the smart charger might not switch to it's maintenance level point.

Brian

[eagle19952]

I believe what Brian said, one or more batteries has a bad cell or are aged out.
A good battery will not boil out that quickly, in my experience.
as long as the plates are covered there is enough water.
Do you use distilled or tap water ?
Wre they my batteries I would do an equalization charge and then a heavy load test.

[PP]

If they were my batteries, I'd check the voltage on each with a voltmeter and make sure you haven't dropped a cell. Then I would check the gravity in each cell and find out what's going on. They boiled out because your charger had a brain fart and cooked them. I had a 'smart' charger do that to me a few years back. I took the charger out of my system and fixed it with clamps and use it as a loaner when someone needs a quick charge on their car or something. I have a hard time parting with things, just ask my DW.
BTW-you can pick up a specific gravity tester for a couple three bucks in most stores that deal with autoparts or batteries. Very handy device if you ever want to know whether to swap out a battery or try to save it.
Will

[Ed Hackenbruch]

I check /top off my batteries on the first of the month. Just part of my maintenance routine.

[Dave5Cs]

Dave, Are your batteries in a 24 volt configuration with a 12 volt center tap. Or just 12 volt.

Dave5Cs

[Tikvah]

It's a 24V system with the Vanner Equalizer... I have a 8ga wire from the Vanner to two 6V golf cart batteries (my house bank).
That's how I charge my house batteries when I drive. 
I have a small 24V smart charger on the pair of big start batteries.  Sometimes I also have a 12V smart charger on the two 6V batteries.

Dave

[Jim Eh.]

BTW. The gasses from a battery are quite explosive especially when charging any battery.

[gus]

It is always better to charge batts separately in case one shorts, happened to me a couple of times.