question

jaredv avatar image
jaredv asked

Connecting 12v power supply to MPPT load output

I want to add a winter/shade 12v power supply to my camper and it would be most convenient to add it to the MPPT 15/75 load output circuit at the fuse panel (i.e. not the chargers solar input)


Would having this additional 12v source present on the "load" side somehow damage or interfere with my charger? Would it be better to hook up an AC battery charger to the battery?


MPPT Controllerscharger
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2 Answers
snoobler avatar image
snoobler answered ·

It should be okay since the load terminals are simply additional controlled connections to the battery.


The load ports should be programmed to be always on, and you can't exceed the load port current rating.


I'm assuming your connection through the DC fuse panel would provide fusing for the wire to the load ports.

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kevgermany avatar image
kevgermany answered ·

Just to add, Victron do this in their Easysolar boxes.

If you have lithium batteries, can disconnect them completely, no need for an external charger. Over winter there is not enough self discharge to make this necessary.

But use a decent multistage charger. The batteries should be charged at float or storage level. If you set this fractionally lower than on the MPPT, the charger will only kick in at times when shading is too much for solar to keep the batteries topped up.

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