Process of Investigation

EVs contain some fuel and ignition sources common to traditional vehicles, and some systems with unique fire risk. The key factors are listed below:

1. There is significant variation in layout and equipment used in EV design; owner’s manuals and service manuals should be consulted for information relevant to fluid and electrical systems for fire risk.
2. EVs generally have coolant for engine cooling and interior heating, hydraulic brakes, windshield washer fluid and may have automatic transmission fluid and other oils. As in traditional vehicle fire investigation, each fluid system should be checked for involvement in fire.
3. EVs operate at voltages well above traditional vehicles increasing the risk of fire due to electrical ignition. Higher voltages result in greater tendency for arcing, higher energy arcs when they occur, and the potential for arc tracking to create conductive pathways in polymers. (For more information about arc tracking, click here.)
4. EV battery packs, with multiple batteries and high voltages, may overcharge individual batteries if the batteries within a pack are not uniformly balanced. Overcharging may overheat batteries or release hydrogen, either condition increasing risk of fire.
5. High-voltage wiring insulation (as well as standard wiring insulation) may become compromised as a result of collision or fire. High energy wiring would be even more likely than 12- or 24-volt wiring to leave observable evidence of a short after the fire.