If you've got an anderson plug connection between your tow vehicle and van, chances are its working at about 20% capacity.
Why? Your vehicle alternator is designed to charge 1x starter battery. Not 1x starter battery + 2x deep cycle, AGM batteries stuck at the end of 10m of undersized cable, running through a corroded anderson plug.
Most vans are wired this way, and as a result, can only charge your van's batteries to 80%, and do so extreeeeemly slooooowly.
The good news is there is an easy fix by fitting a DC-DC charger.
Talk to us about doubling your battery capacity, and halving the charge time with a DC charger.