U.S. Department of Energy - Energy Efficiency and Renewable Energy
Vehicle Technologies Office
A hybrid vehicle uses two or more forms of energy to propel the vehicle. Many hybrid electric vehicles (HEV) sold today are referred to as "hybrids" because it combines a battery system to aid in propelling the vehicle along with a conventional internal combustion engine. A battery system contains a high-voltage battery and a controller working together to provide energy where it is needed. HEVs can use the battery system in two ways, either by giving the gasoline engine assistance when it needs more power, such as going up a hill, or by switching to an electric-only mode when the full power of the gasoline engine is not needed, such as idling at a stop-light. This is accomplished by the controller communicating with the transmission and internal combustion engine to optimize fuel consumption by efficiently managing the power provided to the wheels from the batteries, electric motors, and internal combustion engine.
Battery systems research tests, evaluates, and develops advanced energy storage technologies in close collaboration with developers and the automotive industry. This work is primarily accomplished through the United States Advanced Battery Consortium (USABC), a partnership among the U.S. Department of Energy (DOE), Chrysler, Ford, and General Motors. Through this collaboration, USABC pursues research and development (R&D) of advanced energy systems capable of providing electric vehicles with significantly increased range and performance. This work concentrates on three areas:
- Full energy storage system development for hybrid- and plug-in hybrid-electric vehicle applications;
- Assessment of laboratory-proven technologies and the technology developer's ability to develop and deliver a full-scale, fully packaged battery; and
- Benchmark testing of emerging technologies.
This area aims to accelerate the introduction of advanced energy storage technologies into the automotive marketplace. The work focuses on electrochemical energy storage systems, especially rechargeable Lithium-ion batteries. Researchers maintain a wide range of R&D projects aimed at overcoming the technical barriers hindering the commercial viability of advanced energy storage systems in electric and hybrid electric vehicles.
Research and development projects in the battery systems area focus on evaluating rechargeable batteries and battery components; performing thermal modeling and measurements; evaluating fuel cell/battery and internal combustion engine/battery interactions during simulated driving cycles; conducting failure analysis; and performing diagnostics, safety, and abuse testing. This work has produced a number of test manuals used by many academic and industry battery researchers and developers, including the Abuse Test Procedures Manual, the FreedomCAR Battery Test Manual for Power-Assist HEVs, and the Technology Life Verification Test Manual, which are available from the USCAR Electrochemical Energy Storage Tech Team Website.