Engine Battery Dies After a Week

[Roger D]

'98' Concourse. Has been running great without problems. It could sit for weeks then start right up. Then a few months ago out of the blue it would go dead after sitting a week. The battery is new this spring. I just started it up with the battery sitting with the neg cable off for 4 weeks so the engine battery is good. Solar monitor today showed 12.8 volts on the house batteries before startup, then 14.4V as soon as the engine was running. The strange thing I've seen is with the one way solenoid. Before I started disconnecting the neg cable I found the engine battery dead several times. I put a charger on the terminals and something strange happened. The charger needle went to 5 amps. After very short time there was a load clock from the solenoid and the needle dropped to zero. After a few seconds there was a click and it went back to 5 amps. When that happened I pulled the neg cable and charged without incident. Does this sound like a bad solenoid? Or is there a simple way to check the solenoid ?

[Dano]

Roger;
If I'm not mistaken, your Coach radio is hooked into your starting battery. It could be draining the battery because it has presets that require a small voltage to maintain....maybe look into that?...dano

[chin_k]

The clicks you hear is indeed from the solenoid, when there is any charging source (solar or in your case, a external charger), it start charging the chassis batteries. When the voltage is above a certain threshold, the solenoid connects, and let the charging source start charging the coach battery. The interaction of the charging source and the voltage drop (some due to radio and other parasitic drains, like Dano mentioned above, some due to battery voltage drop when it is not being trickle charged) make the click and the roller coaster amp measurement. The solenoid also will pull a few hundred mA when it is active too.

If your chassis battery is new this spring, then you should get it replaced, and monitor the new battery. Your best practice is to disconnect the negative terminal, but if you do have a charging source (solar, or charger), it maybe a good idea for you to monitor and see what was/is killing your battery. For lead acid battery, it wants to be fully charged as much as possible.

[Roger D]

Finally found the rear closet door wasn't fully latching. Added a magnetic latch and fixed the drain