Chrysler has decided to halt use of 132 prototype plug-in hybrid vehicles after three of the vehicles’ batteries overheated. The vehicles are being withdrawn from service until Chrysler can install an updated battery pack.
Chrysler had launched a fleet of plug-in hybrid Ram pickup trucks and Town & Country minivans to help it research plug-in hybrid technology in the real world. A total of 109 trucks and 23 minivans were given to various utility companies for evaluation, and so far the vehicles have racked up a combined 1.3 million miles of service.
Unfortunately, three of the Ram pickup trucks were damaged when their 12.9-kWh lithium-ion battery packs overheated. Chrysler says that there were no injuries from the battery overheating, and that it occurred when the trucks were unoccupied. The company didn’t specify what caused the overheating, or what damage resulted to the trucks.
Chrysler will work on a new type of battery chemistry, which may allow some of the plug-in hybrid vehicles to return to their fleets at a later date. The company also hopes to add a feature allowing vehicles to send power from the battery packs into the power grid, potentially allowing fleet owners to sell electricity back to the power company.
Both the trucks and minivans use a two-mode hybrid system designed to dramatically improve their fuel economy. Chrysler says the minivans were averaging 55.0 mpg so far, while the trucks had recorded average fuel economy of 37.4 mpg. Those are promising results that bode well for updated plug-in hybrid fleet vehicles.
The plug-in hybrid test program is scheduled to end in 2014.