Electric Vehicle (EV) PDI Guide: High-Voltage Battery SOH, BMS & Charging Diagnostic

Electric vehicles (EVs) have fewer moving mechanical parts than internal combustion engines, but their high-voltage (HV) electrical architecture requires specialized diagnostic procedures. The traction battery pack accounts for nearly 40% to 50% of the entire vehicle value.

1. Traction Battery State of Health (SOH)

Never accept an EV without verifying the battery health. In brand new EVs, transit delays or deep discharge during showroom yard storage can degrade lithium cells. A professional EV inspection connects via OBD-II to evaluate the Battery Management System (BMS), verifying:

• State of Health (SOH) percentage (should be 98% to 100% on delivery).
• Cell voltage variance (individual cell delta should be within factory millivolt tolerances).
• Battery pack temperature sensor feedback.

2. High-Voltage (HV) Cable Insulation & Safety

All high-voltage conduits are wrapped in bright orange protective sleeves. Our technicians perform visual and physical checks beneath the car to ensure no undertray damage occurred during transit that could crimp or abrade high-voltage lines.

3. On-Board Charger (OBC) & AC/DC Port Verification

Inspect both the CCS2 / Type 2 charging gun locking pins and rubber sealing covers. Ensure the port electronic locking latch engages securely when a charger is inserted, and verify regenerative braking calibration during the baseline system check.