house battery not charging when driving rv

It could be just the batteries. Do they perform better after charging on shore power?

X2 on checking the voltage across the battery when the engine is running. You pretty well need 14 V minimum to effectively charge. If there is no change in the voltage as the engine is started, there probably is no connection - fuse or isolator trouble.

If the voltage goes up a little but not to 14V, there may be poor connections. Begin by comparing the voltage across the house battery with the V across the engine battery. If the engine V is over 14 but the house more than half a volt lower, try cleaning up the connections. Half a volt will be lost in a solid state diode isolator, regained by replacing with a relay type isolator.

I had the problem that the house battery did not charge when driving in my Class C. The problem was the solenoid that connects the house battery to the chassis battery when the ignition is on had failed.

You may have a completely different problem. If you have a Class C, check to see if you have a solenoid connected to the chassis battery, check that the solenoid is getting 12v to energize the solenoid when the ignition is on. If it is, check that the voltage on both sides of the solenoid is the same when the engine is running.

The battery not holding a charge may be a bad battery or insufficient charging.

Define "not holding charge when not connected to shore power or generator depletes quickly". What is quickly? Hour? Week? What is running from battery?

How did you determine it is not charging while driving? What are the voltage readings?

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Have you battery tested - most tire/auto parts places will load test for free. Also check for defective fuse/breaker near battery (google "auto reset breaker" for pic as they don't look like typical fuse/breaker). Also - double check and make sure you haven't accidentally toggled the battery disconnect switch.

Almost all the modern coverters will power the rig if your battery is removed/disconnected/bad - that would explain why your rig does OK when connected to shore power.

To get better responses, please advise year, make and model RV you have.

Ours is a Winnebago Class C, which has a relay that connects the alternator output to the house batteries when the engine ignition it turned on.

You have checked the voltage with both the charger, Gen and engine alt. at the battery, and see more than 13.5 v. when either is running? That would be number 1 to deterninbe they can charge a battery.

If it's depleting quickly, a bad battery or a load is still active when not charging is the culprit.

Check that every switch is off, or if you have a main cutoff use it. then check the voltages on the battery as each device is charging, one at a time.

For a Bad battery check: Can you get it(them) out and do a load test? Most Auto parts houses will do it for free.

Let us know what you come up with.