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3S 10A 12V 18650 Lithium Battery Charger Board Protection Module BMS
3S 10A 12V 18650 Lithium Battery Charger Board Protection Module BMS
Professional-grade Battery Management System for 3-cell lithium battery packs with 10A continuous discharge current
Introduction
The 3S 10A 12V BMS is a comprehensive protection and charging solution for 3-cell lithium-ion (Li-ion) or lithium-polymer (LiPo) battery packs. This module provides overcharge, over-discharge, overcurrent, and short circuit protection while maintaining balanced charging across all cells.
Key Features
Cell Protection
3-series lithium battery protection (11.1V nominal)
High Current
10A continuous discharge current (15A peak)
Balance Charging
Integrated cell balancing during charging
Multi-Protection
Overcharge/over-discharge/overcurrent/short circuit
Technical Specifications
| Battery Type | 3S Li-ion/LiPo (18650/26650/soft packs) |
|---|---|
| Charge Voltage | 12.6V (±0.05V) |
| Discharge Current | 10A continuous (15A peak) |
| Overcharge Protection | 4.25±0.05V per cell |
| Over-discharge Protection | 2.5±0.05V per cell |
| Overcurrent Protection | 15-30A (adjustable) |
| Short Circuit Protection | Yes (auto-recovery) |
| Balance Current | 35±5mA |
| Operating Temperature | -40°C to +85°C |
Pin Configuration
| Connection | Description | Wire Color (Typical) |
|---|---|---|
| B- | Battery negative (input/output) | Black |
| B1 | Cell 1 positive (3.7V) | Red |
| B2 | Cell 2 positive (7.4V) | White |
| B3 | Cell 3 positive (11.1V) | Blue |
| P- | Load/output negative | Black |
| C- | Charger negative input | Black |
Wiring Diagram
Protection Functions
Overcharge Protection
Automatically cuts off charging when any cell reaches 4.25V
Over-discharge Protection
Disconnects load when any cell drops below 2.5V
Overcurrent Protection
Triggers at 15-30A (depending on model)
Short Circuit Protection
Instantaneous response to short circuits
Balancing Process
- During charging, BMS monitors individual cell voltages
- When any cell reaches 4.2V, balancing resistors activate
- Higher voltage cells are discharged at 35mA while others continue charging
- Process continues until all cells reach equal voltage (±0.05V)
Troubleshooting
No Output Power
- Check battery voltage (must be above 7.5V total)
- Verify all cell connections are correct
- Test if any cell is below 2.5V (needs recharge)
Not Charging
- Ensure charger provides 12.6V output
- Check C- connection to charger negative
- Verify no cells are above 4.25V (overcharge protection)
Unexpected Shutdown
- Check for overcurrent condition (reduce load)
- Measure individual cell voltages
- Allow module to cool if overheated
Application Examples
E-Bike Batteries
36V battery packs using multiple 3S modules
High-Power Flashlights
Professional lighting systems
Robotics Power
Reliable power for mobile robots
DIY Power Banks
Custom high-capacity battery packs
