An electric vehicle (EV) charging station in New Westminster caught on fire last October, resulting in destroying the charger, damaging the surrounding trees, a streetlight, and a vehicle charging at the adjacent charger.
The charger was not in use when it overheated and burst into flames.
A report from Technical Safety BC has now determined the cause of the fire.
The battery heater was left on after remote HVAC system diagnostic testing resulting in the battery temperature reaching critical levels and starting a thermal runaway and fire.
The unit was placed in a diagnostic mode on Friday morning at 10:00 a.m., 26 hours before the fire by a remote Speed Charge technician in California. While this is normally done for short intervals, the employee failed to return the charger to operational mode.
Leaving the charger in diagnostic mode means regular control of the temperature and safety controls are overridden.
Since the charger was left without safety measures for 26 hours, the battery overheated to the point of critical failure.
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Email alerts that would have notified technicians that there was an overheat in progress were on silent, meaning that the batter was able to continue to operate despite the overheating being in progress.
The retail fuel network representatives and service providers not receiving the alerts prevented actions that may have prevented the incident.
The same remote technician also turned the charger’s heater on through manual controls. The charger reached a temperature of 82°C until it ignited.
After the incident software updates were made to the system to limit the time heaters can be turned on in diagnostic mode and how long a charger can remain in diagnostic mode.
Updates were also implemented to communication protocols for the critical alert system to ensure proper intervention.