Lithium Technology Corporation (LTC) has delivered 95 lithium-ion battery cells to the UC Davis Hybrid Electric Vehicle Group to provide energy storage for the group’s converted Equinox plug-in hybrid electric vehicle (PHEV) competing in the Challenge X engineering competition.
The UC Davis entry—“Trinity”—is a PHEV 40—the electric motors and batteries provide power for driving at low speeds and for a range of up to 40 miles, and the gas engine supplies additional power for longer journeys and highway driving. (Earlier post.)
Trinity is a 2006 model Chevy Equinox SUV powered by electric motors and a small internal combustion engine that can run on gasoline or ethanol, augmented by hydrogen injection. A separate 3 kW hydrogen fuel cell powers auxiliaries.
The lithium-ion cells delivered by LTC to UC Davis for the battery pack each have an output of 3.6 V (nominal) and a capacity of 45 Ah (15.4 kWh total). The nominal battery pack voltage is 342 V, and with each cell limited to 4.2V, the maximum pack voltage is approximately 400 V.
The battery can be charged by either a generator driven by the internal combustion engine (ICE) or a standard AC household electrical socket. The PHEV can drive more than 40 miles on the overnight electrical charge and has a fuel economy of 36 mpg in the city, and 38 mpg on the highway in hybrid mode, as compared to the original range of 19 mpg city and 25 mpg highway. This reflects a reduction in fuel consumption of approximately 68% in city and 39% for highway compared to the standard vehicle.
Challenge X, sponsored by GM and the US Department of Energy, is a multi-year competition to re-engineer a GM Equinox crossover sport utility vehicle to minimize energy consumption, emissions, and greenhouse gases while maintaining or exceeding the vehicle’s utility and performance.
Seventeen university teams are in the competition, of which this academic year is the third year. The sponsors have announced that a fourth-year will be added, with details to come later.
LTC manufactures the GAIA product line of large, high power hermetically sealed rechargeable lithium-ion cells and batteries. In June 2006, the company announced that it was developing, in conjunction with an unnamed automaker, a 12 kWh li-ion battery system that should support a plug-in hybrid application in a four-passenger vehicle with an all-electric range of 60 miles. LTC says that its Li-ion system will be comparably sized to existing battery packs of about half the capacity. (Earlier post.)