3 Series 20A 18650 Lithium Battery Protection Board (3S BMS)

The 3 Series 20A 18650 Lithium Battery Protection Board (3S BMS) is a Battery Management System (BMS) designed to protect and manage a 3-cell (3S) lithium-ion battery pack connected in series. It provides essential safety functions, including overcharge protection, over-discharge protection, overcurrent protection, short-circuit protection, and cell balancing (model dependent), ensuring safe operation and extending the service life of the battery pack.

The protection board continuously monitors the voltage and current of each individual battery cell. During charging, it prevents any cell from exceeding its maximum safe voltage by disconnecting the charging circuit when necessary. During discharge, it protects the battery pack by preventing the cells from dropping below the minimum safe voltage. In the event of excessive current draw or a short circuit, the BMS automatically disconnects the load to protect both the battery pack and connected devices from damage.

Designed to support 3 × 3.7V lithium-ion 18650 cells connected in series, the board provides a nominal battery pack voltage of 11.1V and a fully charged voltage of 12.6V. It supports a continuous discharge current of up to 20A, making it suitable for medium-power battery-powered applications.

Manufactured with high-quality MOSFETs and precision protection ICs, the 3S 20A BMS offers reliable performance, low power consumption, and efficient heat dissipation. Its compact PCB design allows easy integration into custom battery packs while providing stable and dependable battery protection.

The 3 Series 20A 18650 Lithium Battery Protection Board is widely used in battery packs, portable power supplies, electric bicycles, solar energy storage systems, LED lighting, UPS systems, robotics, DIY power banks, power tools (low-power models), embedded systems, and educational electronics projects.

Features

• Designed for 3-Series (3S) lithium-ion battery packs

• Compatible with 18650 rechargeable lithium-ion cells

• Nominal battery voltage: 11.1V

• Fully charged voltage: 12.6V

• Continuous discharge current: 20A

• Overcharge protection

• Over-discharge protection

• Overcurrent protection

• Short-circuit protection

• Cell balancing support (model dependent)

• Low power consumption

• High-quality MOSFET protection circuit

• Compact and lightweight PCB design

• Reliable and long-lasting performance

Applications

• 3S 18650 lithium battery packs

• Portable power supplies

• DIY battery packs

• Electric bicycles

• Solar energy storage systems

• UPS and backup power systems

• LED lighting systems

• Robotics and automation

• Power tools (compatible models)

• Embedded systems

• IoT devices

• Educational STEM projects

• Laboratory experiments

• DIY electronics and prototype development

Package Includes

• 1 × 3 Series 20A 18650 Lithium Battery Protection Board (3S BMS)