The 4S 25A Lithium Iron Phosphate (LiFePO4) BMS Circuit Board with Balancer & Heat Sink from BDTronics is a high-performance battery management system designed to provide complete protection and efficient operation for 4-cell (12.8V) LiFePO4 battery packs. This BMS integrates intelligent cell balancing, overcharge, over-discharge, overcurrent, short-circuit, and temperature protection to ensure long-lasting battery performance and safety.

Equipped with a built-in heat sink, it provides excellent thermal management for high-current applications, making it ideal for solar energy storage, electric bicycles, scooters, DIY battery packs, power tools, and backup energy systems. The same-port wiring method allows for both charging and discharging through a single connection, simplifying installation for both DIY enthusiasts and professional setups.

With ultra-low working power consumption of ≤40uA and compact dimensions of 60 × 33 × 10 mm, this BMS minimizes standby energy loss while being easy to integrate into battery packs. BDTronics ensures reliable performance in a wide operating temperature range of -40°C to +80°C, delivering safety and stability even under extreme conditions.

Features:

• Same-Port Wiring – Allows charging and discharging from the same port for easy installation

• Built-In Heat Sink – Efficient heat dissipation for stable high-current performance

• Intelligent Cell Balancing – Ensures equal charge across all cells to maximize battery life

• Comprehensive Protection – Safeguards against overcharge, over-discharge, overcurrent, short circuit, and extreme temperatures

• Low Power Consumption – Ultra-low working current ≤40uA reduces battery drain during standby

• Durable & Compact Design – Small footprint allows easy integration into battery packs

• Compatible with DIY battery packs, e-bikes, e-scooters, solar energy storage systems, and backup power systems

Discharge:

• Over-Discharge Voltage: 2.3V ±0.08V

• Recovery Voltage: 2.5V ±0.08V

• Continuous Discharge Current: 25A

• Instantaneous Protection Current: 75A

• Recovery Conditions: Charging or load disconnection

• Provides safe discharge management for high-current applications

Charge:

• Overcharge Voltage: 3.75V ±0.025V

• Recovery Voltage: 3.55V ±0.025V

• Continuous Charging Current: 25A

• Charge Balance Voltage: 3.75V ±0.025V

• Balance Current: Up to 40mA

• Recommended Charger Voltage: 15V

• Ensures efficient charging and uniform cell voltage for extended battery lifespan

Installation & Usage Instructions:

• Connect the B- terminal to the battery pack’s negative pole

• Connect the P- terminal to the negative terminal of the charger and load

• Ensure proper cable spacing (2.0mm pitch, 9-pin, 40cm length) for safe operation

• Avoid exposing the BMS to temperatures outside the operating range (-40°C to +80°C)

• Ensure load and charger currents do not exceed rated limits (25A continuous, 75A instantaneous)

• Mount the BMS in a ventilated area to maximize heat sink efficiency

• Use only with LiFePO4 batteries to ensure proper protection functionality

• Suitable for DIY battery packs, solar energy systems, electric bikes, e-scooters, and backup power applications

Specifications:

• Wiring Method: Same Port

• Working Power Consumption: ≤40uA

• Main Circuit Internal Resistance: ≤15mΩ

• Temperature Range: -40°C to +80°C

• Disconnection Protection: Yes

• Cable Size: 2.0mm pitch / 9-pin / 40cm length

• Product Dimensions: 60 × 33 × 10 mm

• Over-Discharge Voltage: 2.3V ±0.08V

• Recovery Voltage: 2.5V ±0.08V

• Continuous Discharge Current: 25A

• Instantaneous Protection Current: 75A

• Recovery Conditions: Charging or load disconnection

• Overcharge Voltage: 3.75V ±0.025V

• Recovery Voltage: 3.55V ±0.025V

• Continuous Charging Current: 25A

• Charge Balance Voltage: 3.75V ±0.025V

• Balance Current: Up to 40mA

• Recommended Charger Voltage: 15V