cewillis wrote:
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.
Having a big, fat wire does not do any good when the voltage coming out of the alternator is <13.5V !
cewillis wrote:
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.
Sorry, that is no longer correct. The PCM now controls the charging voltage based on various different algorithms, not just voltage. This has been the case for all major manufacturers for well over 10 years.
