I have a Ford Transit that has it's own 12v battery system with a 60A usable battery output on it. My house battery is a Lithium Ion 6.5Kwh 24v, connected to a MultiPlus 3000VA, with an MPPT controller for the 900W solar panels on the roof. (Also have a BMV700 and CCGX)
It would be great to charge the battery off the vans alternator to get those 700W coming into the battery when I drive. In winter even 900W isn't enough!
The options I can see are:
1) The Victron Buck/Boost 50A device. This would be nice because it can detect the van engine running automatically without having to figure out the vans electrical system (I know it's possible, but this would be easier!). Most expensive option.
2) Use a cheap 12-48V DC converter and then pump that into a separate MPPT controller to charge the battery. Inefficient? But cheap. And nicely isolated from the vans electrical system.
3) Use a cheap 240v inverter and feed that into the MultiPlus charger with a switch to control the input from shorepower to the inverter. I'd have to remember to change the input current everytime I change sources. And not sure it handles <=700W easily, lowest current input possible is 4.5A (1000W @ 230V).
4) Wait to see if a rumoured DC-DC battery charger from Victron would help (seen on another post). Any suggestions?