My cheapo cell charging and testing equipment

Just wanted to throw up a few photos of what i'm using to process some laptop batterys i got for free from a previous employer,

my testing rig is a ZB2L3 board and i mounted it onto a Arctic Freezer Pro 7 with some epoxy and i mixed some thermal paste with super glue 50/50 and mounted the load resistors on the base of it.

I use two tp4056 charging circuits and made of of my own cell holder by cutting a 9V pp3 connector up and epoxying it onto a old cell holder.

and i'm half way there with the 3S12P pack just wanted to post up some pictures of what i'm upto

Kudos to the DIY work there.

What do you plan on using the pack for once completed?
Why go with 3s? Any specific reason for that voltage range?

Thanks!

I'm a radio amateur operator i'm building this pack with a 30A BMS my radio gear draws around 17A for 100w output, going to be using it for portable operations this summer my equipment is mostly 12v i have already made a small 9 cell 3s3p pack with a 10A bms this powered my 10w radio for nearly 3 hours in the field, Very impressive!

Depending on how many more cells i can get i may start to build an electric bike something like a 10s6p i have some 70 cells at the moment but only 20 something tested.

I would say you should go with 4s, instead of 3s. Then use a buck converter (if needed) to drop you down to 12V steady. You'll get longer run time, and you'll pull less amps from the pack overall, helping to extend cell life.

A switching converter's likely to radiate racket for his ham radio use!
If you want 12V, maybe look at LiFePo4 cells, 4x cells in series = good 12V system match.