4S Li-ion BMS Board 16.8V 30A – Battery Management System with Balancing

4S Li-ion / LiFePO4 BMS – Battery Management System

A high-current 4-series (4S) Battery Management System (BMS) board featuring 16 power MOSFETs for robust overcharge, over-discharge, overcurrent, and short-circuit protection. With onboard cell balancing pads (B+, B1, B2, B3, B−) and separate P− (discharge) and C− (charge) ports, this BMS is ideal for 18650 battery packs, e-bikes, solar storage, and DIY power walls.

Key Features

• 4S configuration: supports 4 series Li-ion cells (16.8V fully charged)
• 16 power MOSFETs for high current handling (30A continuous)
• Cell balancing pads: B+, B1, B2, B3, B−
• Separate P− (discharge) and C− (charge) terminals
• Overcharge protection per cell
• Over-discharge protection
• Overcurrent and short-circuit protection
• Compact white PCB with SMD components

Specifications

• Configuration: 4S (4 cells in series)
• Cell Chemistry: Li-ion / LiPo (4.2V/cell) or LiFePO4 (3.65V/cell)
• Full Charge Voltage: 16.8V (Li-ion)
• Continuous Discharge Current: 30A
• Peak Current: 60A (short burst)
• Balancing: Passive cell balancing
• Ports: B+, B1, B2, B3, B−, P−, C−
• MOSFET Count: 16
• Dimensions: ~70 × 45mm

Applications

• 18650 / 21700 battery pack assembly
• E-bike and electric scooter battery packs
• Solar energy storage systems
• DIY power wall / UPS battery
• Portable power station builds