Welcome to iRV2. Do you have a meter and are you comfortable using it to perform tests on the batteries?
If not, pull the batteries and take them to your local battery store or Auto parts store. Have them:
1. make sure the batteries are at full charge
2. do a load test on each battery.
Without knowing your skill level it is difficult to provide DIY instructions.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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