BMS NMC 4S 20A DALY (11a5s)

DALY BMS NMC 4S 20A (11A5S) is a hardware battery management system designed for 4-series lithium-ion (NMC) battery packs. It protects the battery from over-charging, over-discharging, over-current, short circuit, and temperature faults while maintaining balanced cell voltage for longer battery life. It supports 20A continuous current and is commonly used in DIY lithium battery packs, solar storage systems, electric bikes, and portable devices.

The DALY 4S 20A NMC BMS is a compact battery protection module designed to manage four lithium-ion cells connected in series (4S configuration). The BMS continuously monitors the voltage of each cell, pack current, and operating conditions to ensure safe charging and discharging.

If any abnormal condition occurs—such as over-voltage, low voltage, short circuit, or excessive current draw—the BMS automatically disconnects the circuit to protect the battery pack and connected electronics.

The board also includes a cell balancing function, which equalizes voltage differences between cells during charging. This improves battery efficiency and extends the lifespan of the battery pack.

Because of its 20A current capacity, this BMS is suitable for medium-power battery systems such as electric scooters, power tools, solar batteries, robotics, and backup power systems.

Key Features

• Supports 4S lithium-ion (NMC) battery packs
• 20A continuous discharge current
• Built-in passive cell balancing
• High-precision voltage detection
• Over-charge protection
• Over-discharge protection
• Over-current protection
• Short-circuit protection
• Compact PCB design with heat-dissipation layer