General Motors has awarded advanced battery development contracts to two suppliers to design and test lithium-ion batteries for use in the Saturn Vue Green Line plug-in hybrid SUV.

One contract has been awarded a Johnson Controls - Saft Advanced Power Solutions joint venture.

Another agreement was signed with Cobasys, based in Orion, Michigan, a joint venture between Chevron Technology Ventures, a subsidiary of Chevron Corp., and Energy Conversion Devices. Cobasys will work in partnership with A123Systems, a privately held company based in Watertown, Mass., to develop lithium-ion battery technology.

According to Denise Gray, GM's newly appointed director of hybrid energy storage systems, the companies will be challenged to prove the durability, reliability and potential cost at mass volumes of their technology.

"Thanks to critical relationships with the US government, collaborative research with Ford and DaimlerChrysler under the United States Advanced Battery Consortium (USABC), significant progress has been made in battery research," said Gray.

"But a lot of testing and development is still needed. Together, with our suppliers, we intend to address the issues relating to thermal management, storage capacity, recharge times, driving range and cost reduction."

The two test batteries, one from Cobasys - A123Systems and the other from Johnson Controls - Saft, will be evaluated in prototype Saturn Vue Green Line plug-in hybrids beginning later this year. While both are lithium-ion batteries, the chemistry differs significantly. The suppliers also use unique methods in the design and assembling of the battery packs.

GM will be looking for more partners to bring lithium-ion technology to production. "It's important to point out that these two agreements are by no means the only avenues we're pursuing," Gray said.

"We are fully committed to forging the necessary partnerships to produce battery solutions that will meet our aggressive vehicle programme targets."

GM announced at the 2006 Los Angeles motor show last November its intention to produce a Saturn Vue Green Line plug-in hybrid that has the potential to achieve double the fuel efficiency of any current SUV.

In addition to plug-in technology and a lithium-ion battery pack when ready, the Vue Green Line will use a modified version of GM's 2-mode hybrid system, powerful electric motors and highly efficient electronics to achieve significant increases in fuel economy.

GM is co-developing the two-mode hybrid system with DaimlerChrysler and BMW for use in front-, rear- and four-wheel drive applications in an array of car and truck models.

The two-mode system debuts later this year in the Chevrolet Tahoe/GMC Yukon Hybrid SUVs.