3S 25A BMS Li-ion Battery Protection Board for 11.1V 12.6v 18650 Battery Packs
This 3S 25A Battery Management System (BMS) protection board is designed for use with three 3.7V lithium-ion or 18650 cells connected in series to form an 11.1V 2.6v battery pack. Whether you are building a custom battery pack for an e-bike, power tool, robotics project, or solar energy storage, this BMS ensures your cells remain safe and perform reliably over their full lifespan.
The board features clearly labelled connection pads — B-, B1, B2, and B+ for the battery cells, and P- and P+ for the load or charger — making wiring straightforward even for DIY builders. The included wiring diagram shows exactly how three cells connect through B1 and B2 balance points, providing both cell-level monitoring and pack-level protection in a single compact module.
Protection circuits on board guard against the four most common Li-ion failure causes: overcharge (prevents cells from exceeding ~4.25V), over-discharge (cuts off when any cell drops below ~2.5V), over-current, and short circuit. MOSFETs handle switching at up to 25A, while the control IC provides accurate, stable detection thresholds. The board recovers automatically once the fault condition is cleared.
At just 56 x 45 x 1.2mm, this PCB integrates easily into compact battery housings and custom enclosures. Its low standby current draw ensures minimal self-discharge during idle periods.
Package Contains:
1 × 3S 25A BMS Li-ion Battery Protection Board (HX-3S-FL25A)
