The 2S 20 A 18650 Lithium Battery Protection Board (BMS) is a compact, high-current battery management solution designed to protect two series-connected 18650 Li-ion cells. It ensures safe charging and discharging by providing essential protections such as overcharge, over-discharge, overcurrent, and short-circuit protection. This BMS is ideal for DIY battery packs, robotics, power tools, and portable energy storage where safety and reliability are critical.
Core Board Specifications
• BMS Type: 2S lithium battery protection board
• Battery Support: 2 × 18650 Li-ion cells (series)
• Continuous Discharge Current: Up to 20 A
• Protection Features: Overcharge, over-discharge, overcurrent, short-circuit
Electrical & Interface
• Nominal Pack Voltage: 7.4 V
• Maximum Charge Voltage: 8.4 V
• Balance Method: Passive balancing during charging
• Connection Pads: B+, B−, B1, P+, P−
• Supported Chemistry: Li-ion only (not LiFePO₄)
Performance Characteristics
• Stable operation under high current loads
• Automatic cutoff during unsafe conditions
• Improves battery lifespan through balanced charging
• Reliable protection for DIY and embedded systems
Physical Characteristics
• Module Type: PCB-mounted BMS board
• Form Factor: Slim and lightweight
• Copper Traces: Thickened for high current handling
• Solder Pads: Clearly labeled for easy wiring
Compatibility
• 18650 Li-ion battery packs (2S)
• Robotics and RC systems
• Arduino, ESP32, and embedded power setups
• Power tools and portable electronics
Key Advantages
• High 20 A current capability
• Comprehensive safety protections
• Compact size for custom battery packs
• Essential for safe lithium battery usage
Technical Insights
• Cells should be matched in capacity and health
• Balancing occurs only during charging
• Use a charger rated specifically for 2S Li-ion packs
• Incorrect wiring can permanently damage the board
Applications
• DIY 2S 18650 battery packs
• Robotics and automation systems
• Portable power tools
• Energy storage and backup systems
• IoT and embedded power solutions
Pro Tip
• Always connect the BMS before charging the pack
• Use cells from the same batch for best performance
• Insulate the board properly to avoid short circuits
• Verify individual cell voltages before final assembly
Package Includes
• 1 × 2S 20 A 18650 Lithium Battery Protection Board