There is a lot of interesting info from a talk that Elon Musk gave at the CPUC last week. Of particular note, Musk gave some spec estimates for the mass market “Model E” vehicle expected to be released in 2017 with batteries coming from the Gigafactory. In the video above he says the car will have a 200 mile range and be 20% smaller than the Model S. Therefore the battery will need to have about 80% of the energy of the current Model S (Musk’s words). To be clear, since Tesla uses the constant sized 18650 cells (and looks to continue to do so) physical size and Watt-hours are fairly constant.

So given that a 60kWh Model S has a range of around 200 miles (EPA 208), that means that the Model E would need to have a battery around 80% the size of the Model S or 48kWh.

That’s still about double what leading ‘mass market’ electric cars have today. The Chevy Spark EV, with a range of 82 miles has a 21.3 kWh battery. The Nissan LEAF which has a 75 mile EPA range rating has a 24 kWh battery. The Chevy Volt has a 16kWh battery while the BMW i3 is 18.8.

Tesla cancelled its $49,000 40kWh battery Model S before it got an EPA estimate but most guesses were that it would get around 150 miles.  Add another 8kWh to the battery and take off 20% of the overall car size and 200 mile range seems doable.

Musk also mentions that besides the 20% drop in price, he expects economies of scale and other innovations to drop the price another 30% on the battery alone helping to get the Model E to around 50% the cost of the Model S at $35,000.

Below is a snippit of Musk talking about the upcoming battery swap: