Charge house batteries from alternator or another DC source with compact DC-to-DC chargers. Options include Powerwerx DCDC-8A for LiFePO4, Victron Orion XS and Orion-Tr Smart (isolated and non-isolated) in 12/12, 24/12, and 12/24 models, plus REDARC BCDC dual-input units and a Bioenno car charger.