BMS 4-pin connectors connect the battery management system to external charging, discharging, and communication circuits. Common on 18650 battery packs providing overcharge, over-discharge, and short circuit protection.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | B+ | Battery positive unprotected | PWR |
| 2 | B- | Battery negative unprotected | GND |
| 3 | P+ | Protected positive output | PWR |
| 4 | P- | Protected negative output | GND |