Lithium Battery Charger Protection Module (BMS) 3S 25A 12.6V
The Lithium Battery Charger Protection Module (BMS) 3S 25A 12.6V is a high-performance protection circuit board designed to manage 3-cell lithium-ion (Li-ion) or lithium-polymer (LiPo) battery packs. It offers overcharge, over-discharge, overcurrent, and short-circuit protection, ensuring maximum safety and extending the life of the battery pack.
With a 25A discharge rating, this BMS is an upgrade over the standard 20A version, making it more suitable for higher current applications like e-bikes, power tools, robotics, DIY power banks, and solar storage systems. Its compact design allows seamless integration into custom battery packs, offering reliable performance without increasing size significantly.
How It Works
The module continuously monitors the voltage of each cell within the 3S battery pack. If any cell voltage rises above 4.25V, the charging process is cut off to prevent overcharging. During discharge, the BMS disconnects the load once a cell drops below 2.7V, protecting the battery from deep discharge damage.
The 25A discharge current capability ensures that it can handle devices that draw more power compared to smaller BMS models. Additionally, if the load exceeds the safety limit, or a short-circuit occurs, the module immediately shuts down output to prevent overheating or permanent damage. Automatic recovery ensures that the system restarts smoothly once normal conditions return.
Key Features
Supports 3S Li-ion/LiPo battery packs (12.6V max)
Rated discharge current: 25A
Advanced protection: overcharge, over-discharge, overcurrent, and short-circuit
Built-in balancing for equal cell voltage during charging
Automatic recovery after fault detection
Durable PCB design optimized for long-term use
Compact size for easy battery pack integration
Specifications
| Parameter | Value |
|---|---|
| Battery Type | Li-ion / LiPo (3 cells in series) – |
| Maximum Pack Voltage | 12.6V |
| Rated Discharge Current | 25A |
| Overcharge Protection | ~4.25V ± 0.05V per cell |
| Over-discharge Cutoff | ~2.7V ± 0.05V per cell |
| Overcurrent Protection | 25A (typical) |
| Short-Circuit Protection | Yes |
| Balance Function | Yes (active balancing) |
| Operating Temperature | -20°C to +60°C |
| PCB Size | Approx. 50 × 20 × 3 mm |
Pin Configuration
| Pin/Pad | Label | Description |
|---|---|---|
| B+ | Battery Positive | Connects to the positive terminal of the pack |
| B- | Battery Negative | Connects to the negative terminal of the pack |
| B1 | Cell 1 connection | Between Cell 1 (+) and Cell 2 (-) |
| B2 | Cell 2 connection | Between Cell 2 (+) and Cell 3 (-) |
| P+ | Pack Positive | Output/charge positive terminal |
| P- | Pack Negative | Output/charge negative terminal |
Applications
DIY lithium battery packs
E-bikes and scooters
Portable power tools
Robotics and automation systems
Power banks and UPS devices
Solar-powered storage systems
