BFL13 wrote:
So that one "turns on" with input above 13.2v, so it would not boost to 14.4 when the voltage is at 12.x if you used that Dc-Dc with regen braking? The Sterling one claims it will (I think)
Regenerative braking is a momentary rather than continuous condition. When it occurs, if the DC-DC charger is using the “standard” input triggers, and is already actively charging the aux battery, the “Input Loaded Low Voltage” triggers will be used. It will continue charging until the input voltage hits 9.0 volts. If it wasn’t actively charging when regenerative braking causes the input voltage to drop, then it doesn’t matter. If you are using the “Low Voltage” input triggers, it can turn on and off at lower input voltages, but the input loaded voltage triggers are the same.
BFL13 wrote:
Are you saying that if the Li House BMS shut the Li off there would be no load dump damage to the alternator when the DC-DC has input from the starter battery and not directly from the alternator?
I think the most I can say (not being an expert) is that if you install any DC-DC charger according to the instructions, it’s very unlikely you’re going to damage the alternator. The reason these are becoming more common in the automotive and RV world is because of what has happened with the alternator and charging systems. By connecting a DC-DC charger to the starting battery, it’s just another electrical load on it. It’s not the only one. Again, outside of the marine world, I’m not aware of any DC-DC charger that connects directly to the alternator.
BFL13 wrote:
ISTR advice to connect to the alternator to have less voltage drop, but that was not with Dc-DC chargers maybe.
Yes, on my ‘95 F350, I could get much better charging voltage to the camper battery just by running 6 AWG wires from the alternator. It still wasn’t as good as a DC-DC charger can do, but it was much better than the OEM charging wires. But I couldn’t do that on my current truck. I needed something that the truck ECM wouldn’t even know was there.
:):)
