3s PURPLE 4.2AH 25C Dark Lithium LiIon Drone Battery | Upgrade Energy
1s to 3s Li-ion battery conversion without BMS -(4.2v to 12.6v convert) - Own making - YouTube
4S or 3S 12V Li ion or Lifepo4 Battery smart BMS with Bluetooth function UART and RS485 communication with 60A to 120A constant current – LLT POWER ELECTRONIC