Step 8 – System testing and calibration

Systematically test and calibrate all systems before the vehicle is driven. Each test protects against failure during operation. Do not skip any step — this is the most important phase of the entire conversion.

Procedure

1. Pre-power check: visually inspect all connections, cables and mounts
2. 12V system check: verify all low-voltage circuits operate correctly
3. Insulation test: 500VDC Megger test — must read >1 MΩ HV to chassis
4. BMS commissioning: connect laptop, verify all cell voltages balanced
5. First HV power-up: close contactors manually, monitor for faults
6. Inverter test: run motor at low RPM without driving
7. Throttle calibration: set 0% idle and 100% full throttle pedal positions
8. Regen braking calibration: set levels on overrun and brake pedal
9. Cooling system test: run for 30 minutes, monitor temperatures
10. Charging test: connect EVSE, verify charge current and BMS balance
11. Static drive test: move vehicle forward and reverse in confined space
12. Progressive road test: increase speed in stages to design maximum

Safety warnings

1. Always have a second person present during first HV power-up
2. Keep CO2 extinguisher immediately accessible during all testing
3. Do not exceed 30mph during initial road testing
4. If BMS triggers a fault — STOP and investigate before continuing
5. Notify local roads authority before road testing a converted vehicle

Pro tip

UK converters should consult the DVSA Individual Vehicle Approval (IVA) process. Always get a qualified EV electrician to sign off the HV wiring before road use.