Old Ryobi 40V battery with bad BMS. Harvested the 18650 cells and installed them into a new case. Giving life to the old cells again. Case Kit: www.aliexpress.us/item/325680...
Thank you for the video, I wouldn’t have been able to put them together without it but how are yours performing mine is drastically different from original and drop from 4 lights to 2 almost instantly.
Cells are dead. You need to replace them with similar ones, from what I know the brand is irrelevant, only parameters matter. Search in google where to buy 18650 cells (not on amazon)
forgot one more detail: buy a good charger (I use OPUS BT-C3100) which can "train" batteries: a few charge-discharge cycles. Then let them sit for day-two and check voltage, if it drops below 4v, this battery won't hold the charge.
