Let's compare: the battery pack in a Tesla Roadster today is 53 kWh. The pack in the Chevy Volt? 16 kWh. The Nissan LEAF? 24 kWh. The Hymotion/A123 kit to make your Prius a plug in car uses a 5 kWh battery. Now, how big might the battery in the highest-range Tesla Model S be?
When Tesla revealed the Model S back in March, they said that the car would be available in three flavors: versions that had ranges of 160, 230 and 300 miles. The standard pack, it was revealed, would be 42 kWh, with "70 kWh and greater battery storage systems optional." Jim Motavalli has now gotten Tesla's chief technical officer, J.B. Straubel, to give a first public estimate of how big the 300-mile pack will be: 85 to 95 kWh.
Motavalli easily found plenty of skeptics willing to criticize a pack this big: it'll be too expensive, take too long to recharge and weigh too much, they said. Straubel's response: we have three years to figure this out, and battery technology advances quickly. Sure, but still, 95 kWh? Yikes.