Santa Barbara Develops ZEBRA Battery Electric Bus

April 01, 2002 by Jeff Shepard

The Santa Barbara Electric Transportation Institute (Santa Barbara, CA) is developing a new electric bus powertrain based on the ZEBRA battery. Based on a sodium-nickel-chloride chemistry, the battery is safe, powerful and operates over a wide temperate range of -40 to +150 degrees F. The ZEBRA-powered bus can maintain 40mph on a 2.5-percent grade for brief intervals as high as 50mph. On a 12-percent grade, the speed of the "benchmark" bus drops to 7mph. The ZEBRA bus will maintain 20mph.

The ZEBRA battery module consists of 218 individual cells housed in a sealed steel box that measures 33in x 21in x 12in, weighs 200kg and is rated at 18kW/h. It is a "controlled temperature battery” that requires absolutely no maintenance and is a hermetically sealed product. During normal operation, the battery pack drives two separate inverters. One inverter provides electric power to the drive motors while the second inverter provides auxiliary electric power for air conditioning, hydraulic pumps and similar loads. The inverter also doubles as a 93kW fast charger in the recharging mode. The bus can be recharged from 15 percent SOC to 80 percent in just one hour.

The project has a number of underwriting sponsors, including CalStart, CalTrans, the SMUD, the California Air Resources Board, the LADWP, the SCAQMD and EPRI.