## Maxwell Technologies Lands $13.5M Order for Ultracapacitor Modules for Hybrid Buses in China ##### 24 April 2009  Maxwell BMOD0165 P048 module. Click to enlarge. Maxwell Technologies Inc. has received purchase orders with a total value of approximately US$13.5 million from three of China’s leading transit bus producers for BOOSTCAP ultracapacitor modules to support braking energy recuperation and torque assist functions in diesel-electric hybrid transit buses.

David Schramm, Maxwell’s president and chief executive officer, said that deliveries of the company’s 48-volt BMOD0165 P048 modules, which are assembled by one of its contract manufacturers in China, already have begun and will continue through the balance of the year.

Maxwell’s sales and applications engineering teams have been working with heavy vehicle OEMs in China for the past two years. The company estimates that more than 150 hybrid buses with BOOSTCAP ultracapacitor-based energy storage systems already are in service, and that number is now expected to grow to nearly 1,000 by year-end.

Ultracapacitors’ efficiency in recapturing energy from braking and their low maintenance requirements and long operational life make them an ideal energy storage solution for the demanding duty cycles of electric and hybrid transit vehicles. BOOSTCAP modules have demonstrated reliable performance and high efficiency in the first wave of vehicles that have gone into service, and the ability to connect these modules in series to meet various voltage requirements allows for easy integration into virtually any type or size of heavy vehicle.

China’s leading bus OEMs have developed an array of electric and hybrid drive systems for cleaner, more efficient, transit buses, trolleys and other commercial vehicles. Working with a number of them has given Maxwell a better understanding of the requirements of the heavy vehicle industry and enabled us to expand our presence in the dynamic and rapidly growing Chinese market.

—David Schramm

BOOSTCAP modules meet transportation industry requirements for watt-hours of energy storage and watts of power delivery per kilogram, and are designed to perform reliably through one million or more deep discharge cycles, or about 10 years of operational life for most vehicles, Schramm said.

BMOD0165 P048 modules. The cells used in the modules operate at 2.7 volts, enabling them to store more energy and deliver more power per unit volume than any other commercially available ultracapacitor, according to Maxwell.

The BMOD0165 modules have a nominal capacitance of 165 F, and resistance of 7.1 mΩ. Maximum continuous current is 150A, with maximum peak current, 1 sec, of 4,000A. Power density is 3,900 W/kg, with Pmaxof 7,900 W/kg. Energy density is 3.81 Wh/kg.

BMOD0165 P048 modules are encased in a rugged, splash-proof, aluminum chassis. They weigh 14.2kg and are 12.6 liters in volume (416.2mm x 190.1mm x 156.7mm).

Maxwell 48V Power Modules
Part # Capacitance
(F)
ESR, DC
(mΩ)
Emax
(Wh/kg)
Pmax
(W/kg)
LC
(mA)
BMOD0083 P048 80 12.3 2.48 5,400 3.0
BMOD0110 P048 110 9.5 2.91 6,200 4.2
BMOD0165 P048 165 7.1 3.81 7,900 5.2