Description
2S 10A Lithium Battery BMS for 2 Cells
This 2S 10 A BMS module protects and automatically balances two Li-ion cells (18650, 3.7 V nominal), supporting charging and controlled discharge of a 7.4 V pack.
🔧 Technical specifications
- Configuration: 2 cells in series (7.4 V nominal, 8.4 V maximum)
- Continuous charge/discharge current: 10 A (peaks up to 15 A)
- Balancing current: approx. 20–30 mA per cell
- Standby current: < 10 µA
- Internal resistance: < 300 mΩ
- Overcharge protection: detection at 4.26–4.31 V per cell; recovery at 4.03–4.13 V; delay 700–1300 ms
- Over-discharge protection: detection at 2.82–2.98 V per cell; recovery at 2.90–3.10 V; delay 70–150 ms
- Short-circuit and reverse-polarity protection: immediate cutoff; recovery when the fault is removed
- Thermal compensation: not integrated
- Operating temperature: −20 °C to +60 °C
- Dimensions: approx. 40 × 16 × 3.5 mm
💡 Typical applications
- 7.4 V Li-ion packs for drones, e-bikes, and RC models
- Power banks and DC–DC backup systems
- Portable inverters and DIY mini-UPS units
- Battery test benches and home charging stations
- Embedded projects (Arduino, ESP32) powered by a Li-ion pack
🛠️ Connections / pinout
| Pin | Function |
|---|---|
| B– | Pack negative (battery negative) |
| B1 | Cell midpoint connection (between cell 1 and cell 2) |
| B+ | Pack positive (battery positive) |
| P– | Negative output (to charger / load) |
| P+ | Positive output (often connected to B+; to charger / load) |
Wiring diagram
- B– → pack negative terminal
- B1 → connection between cell 1 and cell 2
- B+ → pack positive terminal
- P– / P+ → terminals for the charger and loads (if separate)
Insulate the module properly and observe polarity during installation.
