Making a Charge Controller for the LEAF Battery Modules

During this week I stared building a Charge Controller for my AESC / LEAF Battery Modules
I have had this idea since last summer: build a simple, effective and safe Charge Controller for LiFePO4 cells, which is in fact a sub-system of my DIY ESS, taking care of the Battery pack charge and discharge functionality

Since the AESC Modules behave like LiFePO4, except for the voltage limits, this kind of controller ill work fine

It is composed of a Programmable Dual Relay Voltmeter, and 2 Tyco Kilovac Contactors, wires, and that's pretty much it !

I even had to read again the DIY ESS Kit documentation to see the wiring of the Voltmeter


and go through their manual to set up some additional values like the decimal point here



and I decided to set up the low voltage limit to : 3.6V x 6 half modules = 21.6V
and the high voltage limit to : 4.15V x 6 half modules = 24.9V (slightly under charge is always safer, since 4.2V is the target voltage on these Lithium Manganese cells)


Higher limit reached => the upper LED is lit and the high relay is open, which will open remove the power from the Charge Tyco Kilovac and stop the Charge .... so simple and effective


Tyco Kilovac not wired yet, but will be done later


and it should stay open until the value I entred is reached, I think it is 23.5V