Raser says its prototype can go 40 miles in all-electric mode before requiring a boost. At that point, a driver can either stop and plug it in, or allow a small gasoline engine to kick in to recharge the lithium-ion batteries.

As for price, Raser spokesman Richard Stern said it should be around $55,000 when mass produced, or about 20 to 30 percent more than a gasoline H3. And the technology is not limited to Hummers, Stern added, noting that any SUV or pickup truck line could be easily converted.