Using solar mppt charge controller as a DC to DC charger

[ofer]

thanks all for the informative replies. i am now off the boat for the winter and will be testing it again next season. for now, i control it via a switch, start stop etc. it works really good for my needs. i just removed my generator and have plenty of power for my needs. no ac needed in Alaska and most heating is done via diesel stoves and heat exchangers.

i can always get a smarter HPPT

 

[folivier]

Renogy has a new DC-DC charger that is also a MPPT solar charger. It can switch from one to the other depending on settings.

 

[Bmarler]

Surely it must have been discussed, but I don’t know if mppt controllers can limit the current they receive. Typically you match the mppt to the amount of panels you have so that the current and voltage line up without overwhelming the mppt charger.
If the mppt can’t limit the current then you may have unpredictable output characteristics as the battery bank can supply extremely high current.