BMS 3S 12V 40A Li-ion Battery DALY

Protect and manage your 3S lithium-ion battery pack with confidence using this DALY BMS, a well-regarded protection board built around a high-quality EIKO IC specifically designed for lithium battery safety. Rated for 3-cell (12V nominal) packs at 40A, this board monitors and controls charging and discharging in real time, preventing the common failure modes that shorten battery life or create safety hazards.

The BMS actively guards against overcharge, over-discharge, over-current, and short-circuit conditions, automatically disconnecting the load or charge path when any of these thresholds are exceeded. A built-in NTC temperature probe adds thermal protection, cutting power if the pack overheats to prevent spontaneous combustion risk. It also includes drop protection, so if a connecting cable comes loose, the BMS simply stops output rather than allowing an unsafe condition, and passive cell balancing helps keep all three cells at a consistent voltage during charging for more even wear across the pack.

This protection board is widely used by hobbyists and DIYers building custom 18650, 21700, or 26650 battery packs for power tools, e-bikes, solar storage, robotics, and other 3.7V lithium-ion applications. Its compact form factor and reliable protection make it a dependable core component for anyone assembling a safe, long-lasting 3S battery pack from scratch.

Specification:

• Configuration : 3S (12V Nominal)
• Continuous Discharge Current : 40A
• Charging Voltage : 12.6V
• Over-Charge Detection Voltage : 4.25V ± 0.025V
• Over-Discharge Detection Voltage : 2.8V ± 0.05V
• Cell Balancing Current : 35mA ± 5mA
• Temperature Protection : 65°C / 75°C (Selectable)
• MOSFET Internal Resistance : ≤10mΩ