I like most RV owner have two battery banks. One bank Lead/Acid, the other AGM. I have a MPPT 100/50 charge controller. Is it possible to charge both banks with one controller. If not, is there an additional device I can employ to accomplish this task?
The best way is to use a DC/DC charger between the two banks. All the Victron DC/DC chargers are unidirectional, that is they will move energy from one battery bank to the other but not the other direction. You need to pick a direction. For example if you want the MPPT on your house battery to charge your starter battery, the input would be the house battery and the output would be the starter battery. If you wanted to charge your house battery with the starter battery, you'd wire the starter battery to the input and the house battery to the output. You could technically connect two DC-DC chargers in opposite directions but you'd need to insure the two units did not energize at the same time or they would chase each other's tail and end up draining both battery banks.
There are some bi-directional ones available from other vendors that WILL move energy in both directions. One such unit is the 3000 watt "Scotty" that also integrates with smart alternator control.
Hi, if they both have the same voltage I'd take the classic way out : connect them in parallel and choose a setting in the mppt that suits both types. 20 years ago the chargers all used cccv, with modern chargers and programs you might gain 5% more power or 5% faster charging, but it's not really a matter of life or death.
