3S Li-ion/PCM BMS Protection Board 12.6V / 10.8V for 18650, 26650 & Polymer Packs — 30A Discharge · 20A Charge (For Screwdriver Tools & 3S Battery Packs)

Overview: This 3S BMS/PCM protection board is built to safeguard and optimize lithium battery packs used in handheld tools and custom 3S assemblies. It delivers reliable protection against overcharge, over-discharge and short circuits while helping extend cell life. Key electrical specs: Designed for cells with nominal voltages of 3.6V–3.7V, the board supports 3S packs (12.6V / 10.8V). Charging voltage range: 12.6V–13.6V. Continuous charge current upper limit: 20A. Maximum continuous discharge current: 30A. Battery compatibility: Works with 18650, 26650 and polymer lithium cells, making it suitable for a variety of battery types and applications, including screwdriver batteries and other portable power tools. Installation and wiring: Connect the pack using the labeled terminals (0V, 4.2V, 8.4V and 12.6V) according to the wiring diagram. Avoid intentional short circuits to prevent board damage. For brush-motor applications, fit a non-polarized capacitor (rated above 25V, 10µF–100µF) across the motor’s positive and negative leads to suppress reverse-voltage spikes. Performance and protection: The BMS manages balanced charging and discharging of the series groups while handling high continuous discharge loads up to 30A. With the specified charge limits and voltage window, the board enables efficient, safe charging without compromising pack performance. Battery monitoring and maintenance: The board allows you to measure the voltage of each series group so you can spot and replace weak or underperforming cells. Regular monitoring helps maintain balance, improve overall pack performance and lengthen service life.