BMS Firmware Development

Key Responsibilities

1. Design and develop embedded firmware for BMS using Embedded C++

2. Implement battery protection algorithms including:

• Over-voltage / Under-voltage
• Over-current (charge & discharge)
• Short-circuit protection
• Over-temperature / Under-temperature
• Cell imbalance and fault handling High-voltage sensing and isolation.
• Precision cell voltage and temperature sensing.
• Current sensing.
• Battery balancing

3. Develop State of Charge (SOC) estimation (e.g., using Coulomb counting, Kalman filters).

4. Develop State of Health (SOH) and State of Power (SOP) estimation.

5. Implement charge / discharge control logic (CC/CV behaviour understanding)

Software Architecture & Design

1. Define and maintain firmware architecture

2. Develop state machines for BMS operation modes (Idle, Charging, Discharging, Fault, Sleep, Shipping mode)

3. Implement bootloader and application separation & FOTA

4. Support firmware update (CAN-based flashing / bootloader)

Communication & Diagnostics

1. Implement and debug CAN communication

2. Experience with UDS (ISO 14229) diagnostics:

• Read/Write DIDs
• Fault codes (DTCs)
• Session control
• Security access

3. Integration with VCU, Charger, Motor Controller, Telematics

4. Develop diagnostic logs and debug interfaces

Testing & Validation

1. Unit testing and bench testing of firmware

2. Characterize and validate BMS performance on battery cell, module, and pack level test benches.

3. Support HIL / SIL / Vehicle-level testing

4. Debug issues using logs, CAN traces, oscilloscopes, logic analysers

5. Root cause analysis of field failures

Collaboration

1. Work closely with hardware, system, and validation teams

2. Create and maintain comprehensive design documentation, including requirements, schematics, DFMEAs, and design review presentations.

3. Support production, manufacturing, and service teams

4. Maintain firmware documentation and change logs

Mandatory Technical Skills

1. Embedded C / C++

2. Real-time embedded systems

3. CAN protocol (Classical CAN)

4. UDS diagnostics

5. In-depth understanding of lithium-ion battery chemistry (Li-ion, LFP, NMC preferred), characteristics, and associated safety concerns.

6. Experience with BMS ICs (TI / NXP / ADI / Renesas / JBD etc.)

7. Version control (Git)

8. Extensive experience with electronic lab equipment for debugging and validation.

9. Debugging using JTAG / SWD