The 4S 20A Lithium Battery BMS Protection Board is designed for 4-series Li-ion battery packs, including 18650 cells. It provides a 14.8V nominal pack voltage and 16.8V full-charge voltage, with protection against overcharge, over-discharge, overcurrent and short circuit.

Full Description

The 4S 20A BMS Protection Board is designed to protect and manage lithium-ion battery packs consisting of four cell groups connected in series.

For standard 3.7V nominal Li-ion cells, a 4S pack has a nominal voltage of approximately 14.8V and reaches 16.8V when fully charged. The BMS monitors the battery pack and helps protect the cells against unsafe charging and discharging conditions.

Protection functions can include overcharge, over-discharge, overcurrent and short-circuit protection. It is important to note that specifications vary between 4S 20A BMS versions: some boards rated as 20A specify a lower continuous current, with 20A representing the maximum or peak current.

Technical Specifications

Important: A 4S 20A marking does not necessarily mean 20A continuous current on every version. Some commercially available versions specify a lower continuous current and 20A as the peak/maximum current.

Product Applications

• 4S 18650 battery packs
• Rechargeable Li-ion battery systems
• Power tool battery packs
• DIY electronics projects
• Robotics and portable equipment
• Backup power systems
• Suitable electric scooter and e-bike applications within the BMS rating