The Ford Motor Co. and Microsoft have announced their plan to offer an online application geared toward helping owners of Ford's plug-in electric vehicles manage their home electricty as their cars recharge.

Christened "Microsoft Hohm," the service will be free to Ford owners. The company will debut five EV models by 2013, beginning with the Transit Connect Electric later in 2010.

The goal of the effort with Microsoft, according to Ford CEO Alan Mulally is "to make the electric vehicle viable, charging affordable, and interaction with the utility grid smarter."

The application will assist owners in determining when to recharge their batteries, with an eye toward encouraging them to draw power from the grid at night when energy costs are lower and overall usage is down.

Microsoft CEO Steve Ballmer described the new service as "a significant step in the development of the infrastructure that will make electric vehicles successful."

Additionally, the venture broadens the existing relationship between Ford and Microsoft that has already developed the Sync voice-control communication and entertainment system installed in some 2 million Ford vehicles since 2007.

The Sync system is standard or optional on most Ford, Lincoln, and Mercury models in the United States, offering hands-free calling and other voice-control options.