Welcome to iRV2. Running the engine a couple of hours may put some charge in the coach batteries but not enough to restore them to where they should be. Not knowing if you have or are comfortable working with a meter this is what I would do.
1. Check the 120 VAC breaker panel in the coach. The breaker for the converter may be tripped. If so, reset it.
Assuming #1 is not the problem:
2. Go to the local auto parts store and get a good multiple stage 12 VDC battery charger. If you want, also purchase a Volt OHM meter at the same time.
3. Place the charger where it can not be affected by rain, etc. Connect the charger to the house batteries. It matters not if the coach has 6 or 12 VOLT batteries. Connect the charger positive lead to the positive battery terminal that has a large (usually red) wire going to the coach. Connect the charger negative lead to the battery lead (usually black) going to ground. If you have a meter, you can double check this connection. These two terminals should have 12 VDC across them. If wired correctly they should correctly span all the coach batteries so the charger will charge all the batteries.
4. Connect the charger to shore power. The charger should have a way to determine where one is in the charging process. If possible leave the charger on until the batteries are in float stage.
5. If you have a meter, see if the converter has 120 VAC coming to it. If not, you'll need to find where the power is being lost from the breaker panel and the converter.
6. If #5 is okay, check to see if there is 13.5+ VDC on the outbound converter connections. You'll need to turn the portable battery charger off to make this check. If there is not 13.5+ VDC coming out of the converter, your fear in the OP is most likely correct.
7. If there is 13.5+ VDC coming out of the converter, then you'll need to determine where the VDC is being lost between the converter and the coach batteries.
Remember to turn the portable charger back on. Above all, you need to make it a priority to get those new batteries back up to full charge.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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