Forum Discussion
StirCrazy
Dec 08, 2020Moderator
theoldwizard1 wrote:
Sometime around 2000, the entire auto industry switched to "smart charging". Smart charging is when the PCM controls the output voltage to the alternator to limit the voltage to "just enough" to replenish the battery after a start and not left the voltage go so low as to discharge the starting battery.
This means that about 5-10 minutes after starting you vehicle the output of the alternator is about 13.2V-13.4V and there is not much you can do about that !
USING HUGE WIRING FROM THE VEHICLE BATTERY TO THE RV BATTERY DOES NOT SOLVE THIS PROBLEM !
The only solution is a DC-DC battery charger mounted close to the RV battery. Most can accept voltages as low as 10V-11V and boost them up to the proper voltage (>14V) to charge a battery.
if your rv batteries are down this should put a load on the system that the PCM will see and it should increase the output accordingly which would mean the larger size wire should work. where your describing would be when the rv batteries are charged and that wouldnt matter much at that point.
it does still leave the questions on weather the voltage will be the ideal voltage for your batteries where a good dc to dc will let you chose charging profiles, instead of just being in bulk the whole time
Steve
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