It seems to work by using a relatively small electric motor to spin a flywheel, running even when the car is stopped. It sounds like an unnecessary drain on the batteries, but it actually enables the large car (loaded down with lead-acid batteries) to be propelled by a small motor that draws less power. It spools up it kinetic energy when you start it, and the flywheel transfers the spinning force to the wheels in a gradual manner. This allows the small motor to operate around its peak efficiency all the time, similar to a CVT. Details are hard to find, which is probably intentional, as Luedtke is trying to sell his designs to a mass-market manufacturer for consumer use. He claims he can get a 150-mile range out of his van, and estimates as much as 500 miles if he equipped it with lithium ion batteries. Whether performance is adequate enough for consumers is a question that likely can't be answered until more funding either from an automaker or private backers fuels more testing in practical and up-to-date prototypes.
Be sure to watch the video of Daren and his electric mini-van.
[Source: OzarksFirst.com Thanks for the tip, Domenick!]