Chassis battery boiling

[Elkhartjim]

I know it's a double post mod's but I've got a problem that I'm trying to get some help with.

Just walked by and smelled something not good. Started looking and one (only one of the two)of the chassis batteries is boiling to the point I can hear it and it doesn't smell so good either.

I'm connected to 20 amps here at the house just to keep the batteries charged and the refer cool. I didn't intend to charge the batteries to the point of boil over.

I unplugged the 20 amps and will wait to hear from y'all. The Mangum inverter/converter appears to be working. The EMS is showing float charge at 13.3V yet the batteries have dropped to 12.4.

Any thoughts ????????????

[MrMudstud]

Let the batteries cool down and check the water level. If the water is below the plates, add only distilled water until the plates are covered or 1/2" below the caps. Then plug in your coach and see if it still boils or smells bad. If it does, then you have a problem with you rig charger.

[Elkhartjim]

Why would it only be one battery? These are the sealed batteries.

[MrMudstud]

I went back and reread your thread. I missed that statement. I was thinking of the house batteries, now I see it was the chassis battery.

If one boils and the other does not, either one is low on water or the battery is bad. You can take off the covers, but they are not meant too. The battery is most probably not good anyway, so for good measure, take the covers off and check the water level. Just for curiosity. Check the connections on each post to make sure they are clean, tight and good. Maybe, the one boiling was getting a charge and the other one was not getting a good charge due to bad connections, and the charger was getting mixed readings. It is worth a try.