Report on the Field Performance of A123Systems’ Hymotion™ Plug-In Conversion Module for the Toyota Prius

A123Systems’ HymotionTM L5 Plug-in Conversion Module (PCM) is a supplemental battery system that converts the Toyota Prius hybrid electric vehicle (HEV) into a plug-in hybrid electric vehicle (PHEV). The Hymotion module is a lithium ion battery pack with ~5.0 kWh of capacity. It recharges by plugging into a standard 110/120V outlet. The system was designed to more than double the Prius’ fuel efficiency for 30 to 50 km of charge depleting range. The Hymotion L5 PCM is the first commercially available aftermarket product complying with NHTSA impact standards. Since 2006, over 50 initial production Hymotion Plug-in Conversion Modules have been installed in private fleet vehicles across the United States and Canada and monitored for performance. With the help of the Idaho National Laboratory, which conducts the U.S. Department of Energy’s (DOE) Advanced Vehicle Testing Activity (AVTA), A123Systems collected and analyzed real-time vehicle data from each fleet vehicle. This paper presents the results of this field evaluation.