Valeo Adopts Maxwell Ultracapacitors for New Hybrid Stop-Start System

SAN DIEGO (July 20, 2007) - Tier 1 supplier Valeo and Maxwell Technologies Inc. have signed a memorandum of understanding to incorporate Maxwell's BOOSTCAP ultracapacitors in Valeo's next-generation Starter Alternator Reversible System (StARS) +X "stop-start" and regenerative braking system for hybrid vehicles.

The new 14+X StARS consists of a reversible starter-alternator, a multi-cell ultracapacitor energy storage module and other power and control electronics in a 14-volt architecture that enables standard gasoline and diesel engines to shut down during idle phases and restart instantly, eliminating fuel consumption and emissions anytime the vehicle is stopped. Valeo estimates that the system can reduce fuel consumption and associated emissions by about 12 percent in normal operation and more than 20 percent in stop-and-go urban traffic.

Unlike earlier-generation StARS with start-stop capability, which did not include a dedicated energy storage component, the new system does and is capable of powering additional electrical functions. The new 14+X architecture incorporates enhanced electronics and an ultracapacitor energy storage module that allows it to recuperate and store energy from braking, which otherwise would be dissipated as friction and heat in a conventional braking system. The recovered energy is then available to power peak electrical loads, such as de-icing and rapid cabin and seat heating and cooling, thus avoiding increased fuel consumption for such functions.

In addition, the flexible 14+X system is easily adapted for integration with a wide variety of existing motor platforms. It can be applied to any new fuel technology, such as flex fuel. This aspect will make time-to-market for new models incorporating the system much shorter than more radical hybrid approaches.

"Because its energy storage employs high-efficiency, low-cost, ultracapacitor technology rather than costly nickel metal hydride or lithium-ion batteries, StARS 14+X can deliver 80 percent of the benefit of a mild hybrid system at 20 percent of the cost," says Daniel Richard, Valeo Electrical Systems' R&D director. "Tax incentives and free access to high-occupancy vehicle lanes have helped to stimulate demand for current premium-priced hybrid cars as niche products, but we believe that mass adoption of low-emission vehicles, and much greater benefits in reduced CO2 and other greenhouse gas emissions, will be driven by the availability of more cost-effective hybrid architectures." 

(Source: The Valeo Group)