My Lithium Ion battery does not seem to be charging correctly during towing. Yesterday 8hr travel, only refrigerator running on propane ~1.25amps. Upon arrival at destination 65% SOC, 13.11V, -16W, -35.9Ah, 1d12hr remaining. This morning after standing overnight w/refrig 57%SOC, 13.08V, -1.06A...