Originally Posted by GaryRudolph
It's wired like above, except the +12V and ground go to the same battery. The original battery was removed and a new one added with the same wiring. The second battery was just piggy backed to the first battery. But, I'd be surprised if a little resistance of a 2 foot cable between the batteries would affect it from charging at all (perhaps on the longevity it could affect it).
the wires should be as depicted for equalization during charging and discharging. The resistance difference of unbalanced wires is small, however even the internal resistance of two unmatched batteries is enough to cause longevity issues for both batteries.
You are correct, though. NO charging is not the problem if they are actually 12 volt batteries wired in parallel. Do they power your camper when not connected to shore power? If so look to the fuse between the generator and the batteries.
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