Hey everyone, we built a very nice electrical system for a customers 2021 Ford Transit and it seems to be plagued with some problems. I have racked my brain, double and triple checked everything, and can't come up with any answers. I'll give a breakdown of the system, then the issues they are experiencing:
200ah Battle Born Lithium batteries
Victron Orion Smart 30amp DC-DC charger
Victron SmartSolar 30amp MPPT charger
Victron Multiplus Compact 12/2000/80 Inverter/Charger
Victron SBP-100 Smart Battery Protect
Victron BMV-712 battery monitor
2 X 100watt Renogy panels
All wiring is Ancor Marine, fusing is Blue Sea Systems
The biggest loads on their system is their Webasto AT2000 heater, and Dometic CFX-65DZ fridge: around 50watts total
Battery drain - while traveling they will regularly wake up and the batteries be at 70%. The heater may kick on a few times at night, but this seems like excessive battery drain.
Battery low voltage - they are getting low voltage warnings from the BMV-712 as well as their fridge; batteries are at 75% charge, but showing low voltage. This seems odd; our experience is that LiFePO4 batteries can maintain high voltage even when discharged.
Odd charging patterns - the other day they drove for an hour in bright sunlight. They should have easily topped off the batteries from the alternator plus solar charging. BMV-712 showed 62% charge. Then 5 minutes later it updated to 100% charge. Is it possible there is a communication error with the battery monitor?
In general, it doesn't seem like their system is charging as well as it should, and the batteries are draining way too quickly. We are out of ideas, as everything seems to be put together perfectly. Any thoughts? What kind of checks can we do? Could there be a parasitic drain on the system, and if so, how do we find that? Could we have a bad ground somewhere? And lastly, could these batteries be damaged if experiencing low voltage?
Thanks for any thoughts/suggestions.