4s 40a BMS Protection Board for 18650 Li-Ion Battery Pack.

The 4S 40A BMS Battery Protection Board is a compact and essential module for building or repairing 4-series lithium battery packs. It is specifically designed for 4S battery configurations made from 18650 lithium-ion cells, including standard Li-ion, LMO, and ternary lithium batteries. This BMS board protects your battery pack against overcharge, over-discharge, over-current, short circuit, and cell imbalance. Integrated balance charging circuitry ensures that all four cells maintain nearly equal voltage during charging, improving battery performance, safety, and lifespan.