The three main factors that affect the life of a rechargeable battery, any rechargeable battery, is chemistry, management, and usage. The same goes for the massive batteries that we find in hybrid electric vehicles [HEV] and electric vehicles [EV].
For the most part, regarding chemistry, Toyota is sticking with tried-and-true nickel-metal hydride [NiMH] battery packs, but the most popular, powerful, and long-lived EV batteries are lithium-ion [Li-ion]. In either case, battery and HEV/EV manufacturers really have no control over how the end user, the driver, charges and discharges the batteries.
One thing they can effect, though, is the battery management system, which controls charging and discharging, optimizing for best power and lifespan. While a lot of research has gone into chemistry, the field of battery management in HEVs and EVs has been somewhat lacking. Some researchers believe that a proper battery management system could increase Li-ion battery power and efficiency by up to 50% without sacrificing battery life.
To that end, the US Department of Energy [DOE] and National Renewable Energy Laboratory [NREL] have announced a new initiative backed by the Advanced Research Projects Agency – Energy [ARPA-E]. The new initiative, Advanced Management and Protection of Energy Storage Devices [AMPED], is based in San Francisco, CA. Backed by a $7.4 million ARPA-E grant, there are at least three projects that are already underway.
Eaton Corporation and the NREL are working to perfect HEV battery management to increase power ad efficiency while maintaining battery lifespan. Washington University is looking to increase Li-ion cell efficiency by about 20%. Utah State University is working to improve EV Li-ion cold-weather power characteristics. “If successful, the advanced sensing, diagnostic, and control technologies developed under the AMPED program will allow us to unlock enormous untapped potential in the performance, safety and lifetime of today’s commercial battery systems,” said Ilan Gur, ARPA-E Program Director.
