100PCS 4S 30A 18650 Li-ion Lithium Charger Protection Board 14.4V 14.8V 16.8V BM

Pack of 100 four-series (4S) protection/charger boards rated at 30A for Li-ion/Lithium 18650 cells, compatible with 14.4V, 14.8V and 16.8V battery configurations. This BMS provides full-cell safeguarding with overcharge detection voltage, over-discharge detection voltage, short-circuit protection and overcurrent protection to help extend battery life and maintain safe operation. Designed for a variety of uses — including power packs and inverter systems — the board is engineered to avoid false triggering and to work reliably across different four-series polymer lithium and four-series 18650 battery assemblies. The compact PCB measures 50mm × 22mm × 4mm for easy integration; connections are made by welding. An optional activation feature is available to accommodate situations with high instantaneous current. For improved thermal performance the board can be mounted to a heatsink; the plain back surface allows straightforward attachment. If a protection event occurs, the unit supports automatic recovery and will resume normal operation without requiring manual reset, offering convenience and reduced downtime.