3S 40A 18650 Lithium Battery BMS Protection Board

The 3S 40A 18650 Lithium Battery BMS Protection Board is designed for building and protecting 3-cell lithium-ion battery packs. It connects three 3.6V or 3.7V lithium-ion cells or cell groups in series to form an 11.1V nominal battery pack with a maximum fully charged voltage of 12.6V.

The board helps protect the battery pack against overcharging, excessive discharge, overcurrent and short circuits. Its 40A rating makes it suitable for battery-powered projects that require higher current than basic low-current protection boards, although the practical current capability depends on cell quality, wiring, cooling and operating conditions.

This BMS is useful for technicians, battery pack builders, electronics hobbyists, robotics developers and DIY project builders across Ghana. DIYGH supplies lithium battery modules, power components and electronics project materials from Kumasi to customers nationwide.

Product Details:
Product Type: Lithium-ion battery BMS protection board
Battery Configuration: 3S
Compatible Cells: 3.6V or 3.7V lithium-ion cells, including 18650 cells
Nominal Battery-Pack Voltage: 11.1V
Maximum Charging Voltage: 12.6V
Rated Discharge Current: Up to 40A under suitable operating and cooling conditions
Connection Type: Common charge and discharge protection board
Battery Arrangement: Three cells or cell groups connected in series

Common versions of this board are marketed with protection against overcharge, overdischarge, overcurrent and short circuit. The stated 40A current is an upper rating, and sellers advise reducing the load when cooling is poor.

Application:
Suitable for 3S 18650 battery packs, portable power systems, robotics projects, DIY battery packs, rechargeable tools, LED lighting systems, small motors, backup power projects, electronics prototypes and STEM battery experiments.

Important Usage Information:
This BMS is not a battery charger. Use a suitable 12.6V lithium-ion charger for charging the completed 3S battery pack.

Use cells with similar capacity, internal resistance and voltage level. Follow the connection markings printed on the board carefully because incorrect wiring can damage the BMS or batteries.

This board is intended for standard 3.6V/3.7V lithium-ion cells. Do not use it for LiFePO₄ cells unless the board is specifically marked for that chemistry.