High-Voltage Battery Diagnostics & SoH Calculation
Methodology for measuring State of Health, evaluating cell module voltage imbalance, and decoding BMS telemetry frames.
Scope & Key Performance Indicators (KPIs)
EV battery diagnostics aim to accurately measure usable capacity loss and pinpoint localized thermal stress risks.
- SoH (State of Health): Usable current capacity (Ah) / Factory nominal capacity.
- Delta Voltage ($\Delta V$): Maximum voltage spread between strongest and weakest cells ($>30 ext{mV}$ indicates fault).
- Internal Resistance ($R_i$): Equivalent ohmic resistance across inter-cell busbars.
- Thermal History: Count of DC fast-charging cycles exceeding $45^\circ ext{C}$.
Standard Telemetry Analysis Sequence
- Connect CAN-bus data logger to the OBD-II diagnostic port.
- Extract individual cell voltage frames under steady load.
- Verify zero isolation leakage faults (e.g., P0A80, P0AA6).
- Calculate coulombic efficiency curve at full charge termination.
Do you have an OBD-II / CAN-bus log file?
Submit your data file to our team for a comprehensive telemetry analysis within 24 business hours.