With RV batteries, they are meant to be discharged to around 50% of capacity then recharged. But the truck ECU charges at 14 volts only for a little while, a very little while, then backs off to 13.5 volts. It takes roughly eleven hours of driving to recharge a couple of RV batteries at that rate of charge. When going from one bookdocking site to another this is impossible. It really gets nuts when the campsites do not allow use of a generator. Solar planels don't work too hot in the shade, and parking in the sun many times means a rig temperature of a hundred ten degrees.
Is there public access data that furnishes parameters that the ECU demands to see without generating a fault code and going into limp-home mode? The data would include alternator field current in relationship to battery voltage, voltage failing to or too slow rising, too high, etc. Putting on a second alternator seems to be out of the question. No room, and modifying pulleys and building a custom bracket would cost thousands of dollars.
