DETROIT — Chevrolet says the Volt plug-in hybrid will travel up to 40 miles on electricity before a small gasoline powered engine has to recharge the lithium ion batteries.

But what if a driver wants to plug in the car when he's away from home?

Two entrepreneurs think they have the answer: Smartlets. That's what Richard Lowenthal and partner Praveen Mandal are calling the electric charging stations they plan to demonstrate in July at the Plug-In Car show in San Jose, Calif.

"We're going to have curbside charging — in parking structures, parking lots, at work and at retail," says Lowenthal, CEO of Coulomb Technologies, of Campbell, Calif.

Lowenthal and Mandal, longtime business associates, incorporated Coulomb Technologies in September.

Lowenthal approached General Motors about Smartlets last fall.

"We said that sounded like a good idea," says Jon Lauckner, GM vice president of global program management.

Although GM is not helping fund Coulomb's venture, the development of a public infrastructure will help support GM's launches of the Volt and Saturn Vue plug-in hybrids. GM hopes to get those to market in 2010. Other manufacturers also are working on plug-in electric vehicles.

Coulomb thinks its meters will be compatible with the Volt, the Vue and other plug-ins, Lowenthal says.

Said GM's Lauckner in an e-mail: "The charging systems of both the Chevrolet Volt and Saturn Vue plug-ins will be compatible with a standard U.S. household circuit — 110 V/12-15 amps. Both will also be able to handle 220 volts."

Lauckner said Coulomb's efforts are useful for the Volt but not mandatory for its initial launch.