My brother gave me his old 500w no brand hubs and esc (hobby wing?) so im gonna slap together a quick 10s4p inr18650mh1 pack
Cells came from ebike battery I snagged from a local shop that ended up with just a bad bms. Woo! Was a 13s4p so extra cells incase any don’t test out. Tore it down and tested them all cap and IR. Discarded the dross and had 45 great cells and the others go to the solar pile as none were that bad really, just not as good as the others.
Matched them up by capacity and IR, each p group will be close to 12.8ah. Perfect for my kid to cruise around on.
Silicone and welding time, pre tinned 4p tabs from duck battery systems. Home jobber wish sourced welder is going to need new probes soon but still makes solid connections
Used a 10-17s 20a llt smart bms (bypassed) because i had it, made the 9 group connection a little funky but idc it turned out good imho. Soldered up the bms and cable connections and set it to balance. Was at a .06v delta when I started, the cells are old and i used 3 different chargers to when testing so they were never perfect. Should be ok though the pac will probably never see 40a
Ive got an opus bt-c3100 and a bt-c3400 for capacity testing and got a RC3563 for internal resistance. Seems to be pretty consistent enough for what im doing. The rc3563 isn’t perfect but its within 2m ohm which is miles better than i was getting from the opus or liitokala chargers for resistance.
Ok so i got it in the shell, shell is vac formed abs: see shitty diy thread. It’s way too weak but idc, looks ok but it is the end of a long series of compromises and failures and i need this board off my work bench. Added foam blocks to secure everything, made up the wiring harnesses and jumpers, cut some more holes for a loop key and xt60 charging port.
I hate how hard it is to make the wires neat and tidy, I die a little inside every time i get to this part. Added a bunch of kapton, fish paper, hot glue to hold temporarily and a fuck ton of silicone to keep things from rubbing in a bad way. Now to let it cure and then close it up for some testing. It will be getting a 1/4 of foam on top of everything to lock everything in place but not until its dry
