I only use my solar system during summer and I'd like to top my batteries off-season with a cheap method. I do not want to invest into another battery charger, so I figured maybe I could simply use the MPPT for this purpose.
asked
Can I charge a battery with a Victron MPPT 75|15 by simply supplying it 17 V DC from a bench power supply instead of connecting it to solar panels?
@peterpan1, it's worth noting that since the MPPT needs battery voltage +5v to initialize, you'll probably want to run your power supply at a minimum of 18v to make sure the MPPT turns on... 17v will only turn it on if your batteries are at <12v, which obviously is well below where they'll likely be sitting.
Otherwise, yes, this definitely works... I use a variable power supply on my test bench to test MPPTs, though I'm usually running at around 22-24v just for the sake of ease. For a 75/15, your only critical consideration is making sure you don't exceed 75vDC in, which shouldn't be a problem.
Yes you can do this,
make sure that the charger can supply a continuous rated 15 amps or you may damage the charger if the batteries are flat etc.
The bench power supply doesnt need to be capable of continuous operation at 15A.
It simply needs to be capable of continious operation at its maximum rating, whatever that is - likely less than 15A.
The MPPT will simply maximise the amount of current available from the source.
