This 3S 40A Enhanced Lithium Battery Protection Board (BMS) manages and protects three series-connected 3.7V lithium cells (like 18650, 21700, or Li-Po packs). Featuring an optimized “Enhanced” hardware layout with lower internal resistance MOSFETs, it safely delivers up to 40A of continuous discharge current while safeguarding your pack against overcharge, over-discharge, and high-load short circuits.