February 1, 2004 – Vol.8 No.45

BETTER THAN BATTERIES?

In hybrid electric and battery electric vehicles regenerative braking is often employed to capture and reuse the energy generated when slowing or braking. In operation, as the driver presses his or her foot on the brake, the vehicle’s electric motor becomes a generator and helps recharge the vehicle’s battery pack.

But battery recharging is a slow process and not all of the energy available from braking is captured. The process helps overall fuel efficiency, but it could be better.

That better solution may be to use ultracapacitors as energy storage systems in hybrid vehicles. Ultracapacitors recharge quickly to full capacity and are drained of electrical energy as demanded by the vehicle. They are also lighter than battery packs and have been proven reliable, according to Maxwell Technologies a manufacturer of ultracapacitors, over hundreds of thousands charge/discharge cycles.

Maxwell has been awarded a production order to supply ultracapacitors for 27, 40-foot hybrid gasoline-electric buses being built for the Long Beach (California) Transit system. The buses will be built by New Flyer Industries and ISE Research.

ISE is so confident of Maxwell’s BOOSTCAP (tm) ultracapacitors that it has given a five-year warranty on its ThunderPack II (tm) energy storage devices which include them. The warranty was a key factor in the transit agency’s decision to purchase the vehicles from ISE and New Flyer. Each ThunderPak will have 288 ultracapacitors.

Visit Maxwell Technologies at http://www.maxwell.com/ , New Flyer at http://www.newflyer.com/ and ISE Research at http://www.isecorp.com/ .