3S 12V 120A Lithium Battery BMS Protection Board with Cell Balancing
This 3-cell series (3S) Battery Management System (BMS) is engineered for 12V lithium battery packs built from 3.7V ternary (NMC) Li-ion cells. Rated at a robust 120A continuous current, it is well-suited for high-drain applications including power inverters, DIY energy storage systems, electric scooters, and power tool battery rebuilds.
The board features a same-port design, meaning both charge input and discharge output share a single set of terminals. This simplifies wiring and reduces the overall footprint of your battery assembly. An integrated cell balancing circuit works during the charging phase to equalize voltage across all three cells, helping prevent capacity imbalance and prolonging the life of your battery pack.
Built-in protection functions cover the full range of common fault conditions: overcharge, over-discharge, overcurrent, and short circuit. These safety mechanisms protect both the battery cells and connected devices from damage caused by abnormal operating conditions.
The module uses a layered PCBA construction topped with an aluminum heatsink cover, which dissipates heat generated during high-current operation and adds mechanical rigidity to the assembly. With compact dimensions of 56 × 86 × 14 mm and a weight of just 120g, it fits neatly into custom battery enclosures.
This BMS is compatible with standard 3.7V 18650 or similar lithium cells wired in a 3S configuration, producing a nominal output of 11.1V (~12V). It is a practical and reliable solution for anyone building or upgrading a 12V lithium battery pack.
Package Includes:
1 × 3S 12V 120A BMS Lithium Battery Protection Board with Cell Balancing
