Oops, battery question

[Itsahobby]

I have a battery charger that has two modes, deep cycle and cranking. I accidentally left it on cranking and changed a deep cycle battery over night. When I went to check on the battery it was boiling and my charger was pretty hot, too. Question is, did I ruin the battery?
Jerry

[502 JET]

If you didnt boil it dry check it with a hydrometer and see if it is still good.You could have warped the plates and shorted it out.The hydro test will tell.

[Itsahobby]

Thanks, I will test it tonight. I didn't realize there is such a difference in the way the batteries are charged.
If you didnt boil it dry check it with a hydrometer and see if it is still good.You could have warped the plates and shorted it out.The hydro test will tell.

[jbone]

I ruined 2 batteries that way. When they stopped holding a charge, I looked at the water level. They were bone dry.
So, like mentioned above, check water level. If it is not ruined, it should be fully charged. Keep an eye on the voltage and if it drops quickly, you have a problem. If it holds around 12.8 or higher it should be okay.
J

[Ike]

Starting batteries have many thin plates inside and can take a charge rapidly, but they also discharge rapidly. This is because you need lots of amps to turn over that starter. However, you cannot discharge a starter battery as much as a deep cycle battery or it simply won't put out the amps you need and the voltage will drop well below 12 volts. For long life about 5% discharge is best before charging.
Deep cycle batteries have very thick plates, charge slowly and discharge slowly. They can be very deeply discharged but will continue to supply the rated voltage and amps down to about 20% (80% discharge) of the battery capacity. But if you try to rapidly charge them at high voltages and current they will over heat and boil off the fluid. The plates may warp and touch each other and over suflate.
As was said, get a hygrometer and test the battery, or take it to a shop and have it tested. Any auto shop or store that sells batteries can do this and they usually do it free.
Here's a good FAQ on batteries. Battery FAQ (http://www.windsun.com/Batteries/Battery_FAQ.htm)