Battery Management System Firmware
Modular firmware based on Zephyr RTOS for low-voltage Li-ion batteries.
GitHub repository: LibreSolar/bms-firmware
Features
- Running on Zephyr RTOS
- STM32F0 and STM32L4 series MCUs (can be easily adapted to other manufacturers)
- Different cell chemistries: Li-ion NMC/NCA, Li-iron-phosphate LFP/LiFePO4
- Pack current and voltage measurement
- Monitoring of single cell voltages
- Control of balancing switches
- State of Charge (SOC) calculation using Coloumb counting and calibration based on lookup tables
- Safety features
- Overcurrent protection
- Short circuit protection
- Overvoltage and undervoltage protection
- Overtemperature and undertemperature protection
- CAN bus and serial interface with ThingSet protocol
Supported boards
- Libre Solar BMS-5S50-SC: 3-5s (12V) BMS with TI bq76920
- Libre Solar BMS-15S80-SC: 6-15s (24-48V) BMS with TI bq76930/40
- Libre Solar BMS-8S50-IC: 3-8s (12V/24V) BMS with Intersil ISL94202
Supported ICs
The firmware allows to use different BMS monitoring ICs, which usually provide single-cell voltage monitoring, balancing, current monitoring and protection features.
The chips currently supported by the firmware are listed below.
| Manufacturer | Chip | # Cells | Status | Datasheet |
|---|---|---|---|---|
| Texas Instruments | bq76920 | 3s-5s | full support | link |
| Texas Instruments | bq76930 | 6s-10s | full support | link |
| Texas Instruments | bq76940 | 9s-15s | full support | link |
| Texas Instruments | BQ76952 | 3s-16s | full support | link |
| Renesas / Intersil | ISL94202 | 3s-8s | full support | link |
API documentation
The documentation auto-generated by Doxygen can be found here.