Accelerated testing of advanced battery technologies in PHEV applications

Abstract

EPRI and DaimlerChrysler developed a Plug-in Hybrid Electric Vehicle (PHEV) using the Sprinter Van to reduce emissions, fuel consumption, and operating costs while maintaining equivalent or superior functionality and performance. The utilization of grid electricity and operating effciency signifcantly reduce petroleum consumption, greenhouse gas emissions, and criteria pollutants, especially benefting urban areas. Southern California Edison (SCE) collaborated with EPRI and DaimlerChrysler to evaluate the vehicle and two different battery technologies. This paper documents one of the first published battery test results related to PHEV applications from the beginning of the project, in September 2004. The partners selected two advanced battery technologies, lithium ion (Li-Ion) chemistry from SAFT and nickel metal hydride (NiMH) chemistry from VARTA. The primary goals of the test are to evaluate the performance and cycle life of traction batteries for future PHEV Sprinter Van production using PHEV test profles. The test profle replicates the most demanding urban driving conditions for the battery (i.e., low speed, high acceleration in charge-sustained HEV mode at low battery state of charge). It also uses a combination of HEV and EV driving modes to represent over 50% of statistical daily trips. One cycle includes three modes: (1) charge depletion mode, simulating the EV operation, (2) charge sustained mode, simulating the HEV operation, and (3) recharge mode, simulating the plug-in operation. The SAFT battery technology shows encouraging results from simulated PHEV tests; one test cycle represents an average daily operation of a PHEV Sprinter Van (i.e., a 2.6-hour, 50-mile drive). © 2008 WEV Journal.