The United States Advanced Battery Consortium (USABC) (earlier post) has selected Maxwell Technologies to begin development of a compact, low-cost, high-performance, 48-volt ultracapacitor-based electrical energy storage module for use in passenger vehicles.
Ultracapacitors, like batteries, are energy storage devices. Batteries store charges chemically, whereas ultracapacitors store them electrostatically. Currently, ultracapacitors are more expensive (per energy unit) than batteries.
However, ultracapacitors provide very quick bursts of energy with more power than batteries, and they can withstand hundreds of thousands of charge/discharge cycles without degrading.
The FreedomCAR requirements for ultracapacitors, for example, specify a cycle life of 750,000 (equivalent to 150,000 miles) and a calendar life of 15 years.
That capability makes them promising devices for the capture and discharge of energy captured by regenerative braking in a hybrid.
In a hybrid electric vehicle, an ultracapacitor-battery combination could significantly improve power management and extend battery life. The ultracapacitor would relieve the battery’s load during high power times, such as initial acceleration and braking. Load-leveling these spikes would allow the batteries to last longer, saving both money and fuel.
USABC operates under the auspices of the United States Council for Automotive Research (USCAR), an umbrella organization formed by DaimlerChrysler, Ford and General Motors to strengthen the technology base of the domestic auto industry through cooperative research.
Maxwell is now eligible for more than $3 million in matching funds for the module development program from the U.S. Department of Energy (DOE) through the FreedomCAR initiative.
Maxwell has more than a little experience with hybrids. When ISE’s ThunderVolt gasoline-electric hybrid bus completed a 15,000 mile test conducted by the Federal Transit Administration last fall, it was using Maxwell ultracapacitors for its electrical energy storage.