Solar Charging LG Chem Batteries While Using BMS


New Member
Hey guys,

I've been using solar for small projects for several years, but I've recently bought some new equipment that I have never used before. I need some advice on how to charge these batteries using my equipment.

The charge controller is a Victron SmartSolar MPPT 75/15. The batteries are LG Chem N2.1 3.6V .

I'm planning to use these in a 4P2S setup. I have never charged lithium with solar and I have never used a BMS. I do have a couple types of BMS units. The two I have are these from eBay:

Can anyone explain to me how to wire this to charge these batteries with solar?

In the past, I have always just connected my panels and battery directly to my controller and I haven't had to worry with a BMS. Now I'm worried about blowing something up because of them being out of balance or something.

Basically, I just want to set this up to get 12 volts out of these batteries to power a Victron Phoenix 12|375. I heard in a YT video, this inverter could run on 7 volts. If that's true, would it be possible just to use 4 of these batteries in a 2P2S setup?

Ultimately, I just need to power some low voltage equipment. I have several devices that will pull less than 100 watts total.



Solar Honey Badger
The BMS is wired in series, so the current goes through the BMS on the (-) terminal of the battery. Hopefully your manual clearly shows this.

You can look up the datasheet and specs for that inverter on I would be surprised if it does. Even if is does, you want to do at least 3S. If it will work a little above 16V, go with 4S.

Keep peak voltage at 4.05/cell and min above 3.3V/cell to get maximum cycle life.