Have plans to leave tomorrow, Wednesday, for a 3 week trip to Lake George, Lake Placid and Cooperstown, New York.This morning went to start the motorhome and nothing. Not even a click. Used voltmeter on battery...completely dead. Went dead over night. Battery is only 2 months old. Took it to Sears this morning and it tested perfectly OK. Connected to motorhome and all starts just fine. Voltmeter shows 12.46 volt. One hour later the voltage drops to 11.1 volts. Something seems to be draining on the battery. Any ideas on what to check and how to check it?Thanks So much.

First thought would be bad alternatorPut meter on battery and get good reading.Start MH and retake reading. Should be 13.5-14.4 volts.Verify connections on battery cables. Verify that the ground to the frame is good.

Bill/Diana wrote:Something seems to be draining on the battery. Any ideas on what to check and how to check it?12.46 is NOT fully charged.You often can not find out what the real problem IS in just a couple of hours.First, you need to fully charge the battery.And then disconnect it and monitor the voltage for a few hours......because even a new battery can go bad.Since this is the "starting battery" (AKA chassis battery), the most common causes are a door left ajar or a dome light left on.More information is needed about the make and model to get specific advice.You NEED a multi-meter to properly test.P.S. I suggest that it would NOT be a good idea to leave on a trip tomorrow......unless you find out for sure what the problem IS.

That's a big drain, and tough to find. I have a car that does that, not as bad, but I simply disconnect the battery if I'm stopped for more than 1 hour.

I smell a rat...Even a constant 10-amp bleed would spark like crazy and I am to believe no-one NO ONE noticed a blue and yellow mega-spark while the charged up battery was being reconnected two times by two people?Charger up again but leave disconnected overnight. If it loses >.20 volts you have your gremlin. If the rig has a generator you have your charger options. Troubleshoot at your campsite. You'll gather 2-tons of fender squatters (neighbors) kibitzing every move you make.

Your profile does not show make, model and chassis of MH.A bad diode in the alternator regulator could cause such a drain.test I suggested could show this.

Ghost Battery Drain | Good Sam Community

2oldman
Explorer II
Jul 16, 2019
That's a big drain, and tough to find. I have a car that does that, not as bad, but I simply disconnect the battery if I'm stopped for more than 1 hour.
Sam_Spade
Explorer
Jul 16, 2019
Bill/Diana wrote:

Something seems to be draining on the battery. Any ideas on what to check and how to check it?

12.46 is NOT fully charged.

You often can not find out what the real problem IS in just a couple of hours.

First, you need to fully charge the battery.
And then disconnect it and monitor the voltage for a few hours......because even a new battery can go bad.

Since this is the "starting battery" (AKA chassis battery), the most common causes are a door left ajar or a dome light left on.

More information is needed about the make and model to get specific advice.

You NEED a multi-meter to properly test.

P.S. I suggest that it would NOT be a good idea to leave on a trip tomorrow......unless you find out for sure what the problem IS.
enblethen
Nomad
Jul 16, 2019
First thought would be bad alternator
Put meter on battery and get good reading.
Start MH and retake reading. Should be 13.5-14.4 volts.
Verify connections on battery cables. Verify that the ground to the frame is good.

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