3S 20A 12V Lithium Battery BMS Protection Board for 18650 Cells
This 3S 20A Battery Management System (BMS) protection board is engineered for 3-series 18650 lithium-ion battery packs operating at a nominal 12V (12.6V fully charged). Designed to the REV 2.0 standard, it provides essential safeguards that extend battery life and protect connected devices.
The board handles up to 20A of continuous discharge current, making it well-suited for demanding loads such as cordless electric drills, DC motors, and similar power tools. Its overcharge and over-discharge protection circuits prevent individual cells from exceeding 4.2V or dropping below safe discharge thresholds, while integrated short-circuit protection cuts power instantly in fault conditions.
At just 59mm × 20mm and 5 grams, the compact surface-mount PCB fits comfortably within tight battery enclosures. The onboard dual MOSFET design ensures low resistance switching for both charge and discharge paths, keeping heat low during operation. Voltage tap points (0V, 4.2V, 8.4V, 12.6V) are clearly labelled on the board, simplifying wiring and assembly.
The board supports a 2-in-parallel, 3-in-series (2P3S) cell arrangement, allowing builders to increase capacity while maintaining the 12V output. It is a reliable and cost-effective solution for DIY battery pack assembly, power tool repair, and electronics prototyping.
Package Contains:
1 × 3S 20A 12V/12.6V Lithium Battery BMS Protection Board (REV 2.0)
