When Chrysler reveiled their three ENVI vehicles a few weeks ago we found that one of them was an all electric sports car for Dodge.  Likely a replacement for the Viper (Chrysler is looking to sell the Viper name for some cash, the new CAFE standards preclude Chrysler from making the Viper in a few years).  The Dodge EV with it’s batteries would have a range of over 150 miles, but that’s not very practical for every day buyers.  Then again, a Viper isn’t that practical either.

The other two EVs are extended range electric vehicles (that’s GMs term for it).  They use batteries for the first 40 miles to power an electric motor that drives the wheels and then a gas engine switches on to extend the range.  The Chevy Volt does the exact same with it’s engine and motor.  The question has been, does the gas engine bypass the batteries like the Volt does, or does it run a generator that recharges the batteries so that the batteries will always power the electric motor.

“The gas engine recharges the battery a little bit,” said Cole Quinnell, a Chrysler spokesman. “But that’s just excess and overflow, not the central intent. It’s more efficient for the gas motor to drive the wheels, not recharge the batteries. The cost to recharge the battery by running the generator is eight times the cost of taking it home and plugging it in.”

Along with the actual dollar cost of using gas to recharge the batteries the longevity of the battery pack is a consideration for this decision.  Rechargeable batteries have a lifespan of only so many charges.  Having the gas engine constantly recharge the battery pack would shorten the life of the batteries significantly.