theoldwizard1 wrote:
Much simpler and probably more effective is a DC-DC charger.
Modern vehicles vehicles drop the voltage from the alternator to <13.5V shortly after starting. This has is not adequate to charge a house battery. The DC-DC charger boosts that up to the proper charging voltage.
Adequate current transfer is still required in any case -- thus heavy gauge wire.
My alternator - and I suspect all functioning alternators - charges at a voltage determined by the load voltage. While the load voltage is below ~14.3 to 14.4v, the alternator charges at ~14.4 volts. When the load voltage comes up, the alternator drops to the maintenance voltage of ~13.5v. Otherwise, the load (batteries - truck + camper) would never reach full charge.
