Description
The 3S 40A Lithium Battery Protection Board (BMS) is a compact battery management system designed to protect 3-cell lithium-ion battery packs connected in series. It provides essential protection and basic cell balancing to improve safety and extend battery life in medium-to-high current applications.
Key Features
-
3S Configuration
Designed for 3 lithium-ion cells in series (3S) - Nominal voltage: 11.1V
- Fully charged voltage: 12.6V
- High Current Capability
- Rated up to 40A peak discharge
- Practical continuous current: 25–30A (depending on cooling and PCB quality)
- Comprehensive Protection Functions
- Over-charge protection
- Over-discharge protection
- Over-current protection
- Short-circuit protection
- Cell Balancing Function
- Passive balancing to maintain equal cell voltage during charging
- Helps improve pack lifespan and stabili
- Enhanced Power Stage
- Multiple parallel MOSFETs for lower resistance and improved current handling
- Thick copper traces and large solder pads for high-current connections
Specification
- Cell Configuration: 3S (3 cells in series)
- Battery Type: Lithium-ion / Lithium-polymer (NOT LiFePO₄)
- Nominal Voltage: 11.1V
- Maximum Charge Voltage: 12.6V
- Maximum Discharge Current:
- Peak: 40A
- Recommended continuous: 25–30A
- Balancing: Yes (passive balancing)
- Protection Functions:
- Over-charge
- Over-discharge
- Over-current
- Short-circuit
- Operating Temperature: Approximately -20°C to +60°C
- Board Marking: HW-287 / 3S 40A
Application
- DIY lithium-ion battery packs
- Power tools and portable equipment
- Robotics and motor control systems
- Inverters and DC loads (within current limits)
- Custom electronics projects requiring 12V lithium packs.