University of Extrication: Electric Plug-In Vehicle Extrication Techniques Part 3

July 1, 2013

The 'floorpan-mounted' high-voltage battery of the Mitsubuishi i-MiEV weighs approximately 500 pounds. The entire vehicle weighs approximately 2,500 pounds so it is apparent that the vehicle is 'bottom heavy.' This is important to consider when stabilizing this vehicle. The floorpan battery is visible below the vehicle in this image. — The "floorpan-mounted" high-voltage battery of the Mitsubuishi i-MiEV weighs approximately 500 pounds. The entire vehicle weighs approximately 2,500 pounds so it is apparent that the vehicle is "bottom heavy." This is important to consider when stabilizing this vehicle. The floorpan battery is visible below the vehicle in this image.

SUBJECT: Electric Plug-In Vehicles

TOPIC: Challenges of Floorpan-mounted High-voltage Batteries

OBJECTIVE: Understand procedures necessary for dealing with an electric plug-in vehicle with a floorpan-mounted high-voltage battery

TASK: Given an electric plug-in vehicle with a floorpan-mounted high-voltage battery to review and inspect, the rescue team shall revise their existing procedures for dealing with the vehicle including unique vehicle stabilization considerations

Our series on electric plug-in vehicle rescue and extrication continues with a focus on the unique challenges presented by floorpan-mounted high-voltage batteries. The vehicle featured in this series is the Mitsubuishi i-MiEV which has its high-voltage battery mounted completely beneath the metal floor of the vehicle. Electric cars such as the Tesla Model S and the Nissan LEAF also mount their large high-voltage battery under the floor. This “floorpan” location requires that responders make some adjustments to several routine rescue and extrication tasks that might be necessary at an incident.

With the 330-volt, 16 kWh lithium-ion battery of the i-MiEV positioned in this floorpan location, the weight distribution of the electric vehicle changes from that which responders have become accustomed. The i-MiEV is a rear-wheel drive electric vehicle that has 45% of its total weight in front of the firewall area with 55% towards the rear of the vehicle.

An electric plug-in vehicle’s center of gravity is also different from that of a conventional vehicle when the high-voltage battery is underneath the floorpan. Rescue personnel should consider electric plug-in vehicles with floorpan batteries as being “bottom heavy.” The weight and location of the high-voltage battery influences the way we accomplish vehicle stabilization; especially when the vehicle is side- or roof-resting. It also limits any tasks that involve cutting into the floorpan or pushing against an interior component that would crush the floor of the vehicle.

TASK: Given an electric plug-in vehicle with a floorpan-mounted high-voltage battery to review and inspect, the rescue team shall revise their existing procedures for dealing with the vehicle including unique vehicle stabilization considerations.

Read the rest of the series here:

Part 2

Part 4

About the Author

Ron Moore

RON MOORE, who is a Firehouse contributing editor, recently retired as a division chief with the McKinney, TX, Fire Department and now serves with Prosper, TX, Fire Rescue. He self-published the Vehicle Rescue 1-2-3 training manual and serves as the forum moderator for the extrication section of Firehouse.com . Moore can be contacted directly at [email protected].