I'm sure it has already been mentioned but if we mention it enough, someone at GM might take notice: I wonder if they will add an optional battery pack that can increase the milage beyond 40 miles before the gas engine kicks in? I think an "extra capacity" battery option would be great for those who drive more than 40 miles per day to work and other places, ie. one that would allow the Volt to go 60 miles (or more) before the range extender kicks in. Then the only time you would ever have to use the range extender is for out of town trips to grandma or the beach. I know space might be a factor here to consider. Since the current battery fits under the car, making it have greater capacity would mean making it larger of course. One idea would be to add the extra battery length extend into the trunk area. Another idea would be simpler: Have a simple connection in the trunk for an additional battery pack to connect to the main battery. If GM does not come up with an option like this i'm almost certain some after market option will be out there that will be made by another company. Isn't there a company that will upgrade a Toyota Prius to make it a plug by adding a battery pack that would allow it to get about 100 miles per gallon?

Actually, I think a more feasible scenario is the introduction of a "Gen-II" battery around 2013 that doubles the electric range, but has the same "footprint" as the Gen-I battery. Owners will be sent a notification letter and giving them the option to upgrade.

I think over the next few years, we're going to see the power density of automotive lithium-ion batteries increase exponentially.

If GM is smart, they'll keep the pedal to the metal with battery development, and make them reverse-compatible with previous models. I'm sure 100 miles of all-electric range is one of their internal benchmarks for future development.

Good suggestion also. I do like the idea of being able to "upgrade" a current battery for an extended battery when developed in the near future after the Volt is released, but it will depend on the cost of course. If the upgrade costs $10K, it might be better to trade the old Volt in on a new model. I'm still hopping that an extended battery option will be available. The solar roof option seems like an great idea, but how much power will it generate? I've heard that it would take 2 weeks in the sun for the optional panel to recharge the battery completely.

Good suggestion also. I do like the idea of being able to "upgrade" a current battery for an extended battery when developed in the near future after the Volt is released, but it will depend on the cost of course. If the upgrade costs $10K, it might be better to trade the old Volt in on a new model. I'm still hopping that an extended battery option will be available. The solar roof option seems like an great idea, but how much power will it generate? I've heard that it would take 2 weeks in the sun for the optional panel to recharge the battery completely.

Actually, if you travel a lot and park in an outdoor lot, 2 weeks is probably about what an extended business trip or vacation would last. Doesn't sound all that bad to me! :)

Has anyone heard anything about what the deal's going to be about whether the battery is going to be leased separately from the car or not? If the battery is a lease, I think an "upgrade" option would be a lot more feasible.