Tow vehicle charging RV batteries
How slow is it? Is there a mod you can do to make it charge quicker? I was watching a video where some ppl that like to boondock said the alternator doesn't charge the batteries on your RV very qui...
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blaczero wrote:
How slow is it? Is there a mod you can do to make it charge quicker?
The real issue is how large is your battery bank and how depleted is it (what is its "state of charge" SOC ?)
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 !
So if your RV battery is at the end of 25' of wire (actually double that because you have a ground connection) you will be darn lucky to get 13.0V, probably less. You can NOT charge a lead acid battery on that little voltage. 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.
