Battery Charging Problems

Artum Snowbird wrote:

Put your meter on the converter output terminals. You should show 13.6 if the converter is working.

Make that MINIMUM voltage.
13.6 is about "float" voltage and won't charge much.
If your converter never goes above 13.6, either it is a cheap unit or it isn't working right.

I agree that some clarification of the situation is necessary.

Shore power and generator power are both 120 volts. That power needs to go into your converter to produce the 12 volts needed.

Put your meter on the converter output terminals. You should show 13.6 if the converter is working.

Now, if that is the case, you need to get that to the battery. It might be the positive feed to the battery, or the negative.

The best way to check is take your jumpers and connect to your battery positive and battery negative. Take the other end of your jumpers into your rig, and with a strong wire, first connect the negative to the negative output. If your lights all of a sudden get bright, you have a loose connection in the negative wire.
If nothing happens, remove the negative jumper, and connect the positive to the converter positive. If the lights get bright, you have a loose connection in the positive wire.

If that doesn't work, connect both positive and negative. Let me know what you find.

In my case, the negative heavy feed wire connection to the battery was loose in the terminal strip at the converter.

Also a good idea to tighten all the wires in there. Check the battery terminals for the negative and positive feed wires.

The alternator charges because that is a 12 volt connection to 12 volt connection.

Go to you local parts house most will put on a battery tester and can put a load on and check battery cells. He can also check charging system and tell you if it is healthy or not best of all most do not charge a dime for it. and you didn't get you hand dirty LOL.

It's also not clear which battery bank you're referring to with your numbers. The alternator should charge both banks. The charger charges the house battery and may/may not charge the chassis battery.

Bad/weak batteries can cause strange/unexpected results. Have all of the batteries load tested.

If you mean the charger reads 13.5V AND the battery reads 13.5V (at the battery posts) then disconnecting the battery and it drops to 11.5V then you likely have a bad battery. Have the batteries load tested.

Shore power and gen both supply AC power to the charger to maintain the batteries so expect the same for both. The gen may use some DC power and the batteries can drain w/o charging.

BTW Inverters convert 12V DC to 120V AC. They do not charge batteries. If you have a charger/inverter unit then the charger portion charges the batteries.