Sheddi's power bank build thread

[sheddi]

My 60Ah lithium iron phosphate (LFP) cells for my AC-coupled solar storage battery have arrived today. I thought I'd post some photos to show how they *could* be used for a power bank if you were so inclined.

This first photo shows four cells configured as a 60Ah, 12V-nominal battery (720Wh) next to my 50 cal ammo box:



As you can see, there's room in the box but you wouldn't have much space above the cells for anything else. I think you would struggle to fit eight cells into the box.

The second shows me charging them through a very basic 4S LFP BMS. I'm using this because my 3.6V power supply is only capable of 2A, and charging 16x 60Ah cells in parallel at 2A would take, roughly, a month and a half. By building them into a 12V pack I can charge them with my 12v, 5A charger and let the BMS take care of things.



The cells are these ones and the 4S BMS is this one (I did say it was basic). At current prices the parts for this 12V 60Ah battery are a total of US$106 and change. (Lugs and cable will be extra.)

I have a sneaking suspicion the cells aren't really 60Ah - one Aliexpress reviewer says 50Ah and there's a sticker on one of the cells saying the same - in which case it's only a 600Wh battery. Still great value IMHO.

Edit to add: I have taken those first four cells off charge as I don't really want to leave them charging unattended overnight. so far they've had 8 hours at 5 amps, so they're at least 40Ah

[wee drop o bush]

We've just gotten solar panels installed and linked up to our smart meter. Our house usage on standby is only 0.4 KW, its 3 KW just to boil the kettle   The panels are well situated but it's overcast today.
We are now wanting more panels and some storage batteries, as we get pittance for excess KW going to the grid.