DC-DC Charging ?
When you add a DC-DC charger from the truck as in several threads about that, does that put the house batts in parallel with the engine batt? (as with normal "alternator charging" via 7-pin) Or is...
Forum Discussion
BFL13 wrote:
I like the always live 7-pin on my Chev. When the camper is on, and parked for a long time, the shore power to the camper converter floating the camper batts also floats the truck batt.
With the 5er it was not an issue since the 7-pin is disconnected when you un-hitch and move the truck away.
Without that, I need another maintenance charger for the truck batt. I have to use a second charger for the Ford Class C to keep the engine batt up when parked a long time.
Since I don't want to mix batt types now, I have to use a separate charger for the truck batt anyway. With the Renogy installed there is no choice, so separate charger for the truck still needed.
Sounds like your going to need two separate charge lines, or some complex relay switching to make what you want to do work.
One line to charge the RV from the vehicle when ignition is on and one from RV to charge the vehicle from the RV..
Relays will use power when activated, Bosch cube styles are around 250ma-350ma (3W-4.2W). Not much concern for the vehicle side when ignition is on but it is a drain on the camper side when vehicle is not running..
Have to be careful about using "solenoids" several styles of those, some designed for intermittent duty (like starting) some are designed for constant on use and some are a ratchet style that uses a impulse to the coil to switch on/off.
One of the downsides of automotive (starting or constant) solenoids is the coil draws more current than a relay which needs to be accounted for..
