Jump-start design: Ultracapacitors booste engine starts

By Control Engineering Staff October 5, 2006

System integration sometimes involves looking at tried and true (tired and blue?) technologies and updating the designs. In most vehicles, batteries power a starter that cycles the engine until it starts. It’s been that way since starters replaced hand cranks. Integrating an ultracapacitor into the mix is said to improve starting performance, lower cost, reduce cabling, and extend battery life.

Maxwell ‘s Boostcap ultracapacitors will be integrated into a highly efficient, low-cost, engine starting system for automobiles, under a recent agreement between Maxwell Technologies Inc. and Kromberg & Schubert GmbH & Co. KG, a leading global supplier of wire harnesses and electrical and electronic components to the automotive industry. Richard Balanson, Maxwell’s president and chief executive officer, cited testing and analysis that shows how an ultracapacitor-based starter power node located in close proximity to the starter, relieves the “battery of the demanding short-duration, high-current, starting load provides several benefits, including extending battery life, downsizing the battery, and reducing cabling.”

Kromberg’s Arthur Kurz, manager electronic integration, said that ultracapacitors’ burst power capabilities, cold temperature performance and long cycle life make them particularly well-suited for vehicle starting. “Automotive batteries store a great deal of energy, but must be over-sized to deliver current rapidly enough for acceptable starting performance, and their ability to deliver such current drops off sharply when the temperature approaches freezing,” Kurz said. “Ultracapacitors store less energy than batteries, but can deliver ample current for starting at temperatures as low as -40 degrees.” A system combining batteries and ultracapacitors provides system advantages.

Kurz pointed out that many newer automotive designs place the battery in the trunk area, which requires running a heavy, rigid, expensive, 70-90 mm copper cable the length of the car to provide sufficient starting current. However, he noted that a system employing a small ultracapacitor-based power module located near the starter can be charged by a lighter, flexible, less expensive, 16-25 mm cable, a lighter, less complex wiring design, using less copper. Kurz added, “Our calculations show that the system will pay for itself by lowering wire harness cost and reducing the size and extending the lifetime of the battery, as well as contributing to improved fuel efficiency by lowering vehicle weight.”

Balanson said that Maxwell continues to work directly with transportation and automotive OEMs as well as other tier 1 suppliers worldwide to design and develop innovative energy storage and power delivery technologies.

Kromberg & Schubert GmbH & Co. KG, Headquartered in Abensberg, Germany, is a global supplier of wire harnesses, special cables and wires, plastics, grommets and other electrical and electronic components mainly for the automotive market. Maxwell is said to be a leading developer and manufacturer of innovative, cost-effective energy storage and power delivery products.

— Edited by Mark T. Hoske ,editor in chief , Control Engineering