here is my first battery, cells are samsung salvaged 1500ma,10s 9p, roughly graded and built into a jumbo shark case, the supplied BMS wouldnt work so cut it out and went without one, i was keen to get rolliin, drive is rear hub 500watt with 250 watt control giving 10mph on a voodoo banttu mtb, all was fine for a week,then a series died ,reversiing polarity, that was replaced so 9 dead batteriies, this happened twice more so 27 dead total, i did find 2 bad conections on the string next door, the circuit board welder wrked well with a 100 amp old truck battery, i assumed it would work as well with a smaller car battery so recycled the truck battery, a mistake. so time to add a BMS,a load test of 3 twelve watt bulbs[i am a fully qualified sparks but refuse to call them lamps because thats BS] ran the load for 23 hours so 828 watt hour,828÷36v= 23 ah battery, with bms iin place, plugged in the charger, indicator light red,, so it was charging, took much longer to charge with the BMS in situ, so i guess before it was getting to 42V by overcharging some striings and undercharging others, and now its takiing time to balance the strings, so off i set, 20 miles at 10mph with no peddling, would have liked the legal max 15mph, may use thinner tyres to get the speed up, not going aboove 250 watts as have a motorcycle, the range is down to 5 milesthen the BMS shuts the unit down, thiis happened 2 days n a row, happened again today, plugged in charger and the light went from red to green straight away, i suppose the bms isnt happy, so lid off the pack, bulk chargiing, im not wrapping again tiill i get this thing down patt, picked up 108 20700 cells,next purchase the opus bt charger/discharger so i can get capacity values, full grading of cells, dally bluetoothe BMS, newish truck battery for welder, just found this forum and learning much,please no warnings of catostayfy and doom, i have a large bread bin and will pop it in should meltdown occur, all the best
