Tesla's Model 3 won't have a 100 kWh battery to start

But it's unclear which power source they'll choose for the more economical car.

Stephen Lam / REUTERS

Tesla's started off 2017 with a bang, officially opening its Powerpack-filled 20-megawatt energy storage station in Mira Loma, California last week as it looks to start production of its Model 3 at the end of the year. Just don't expect its new, more affordable electric car to come with the larger batteries they stuck in their existing vehicles last year: CEO Elon Musk himself finally confirmed that the Model 3 won't initially come in 100 kWh.

For its Model S and Model X cars, Tesla expanded beyond the 60 kWh baseline batteries, which get about 218 miles of EPA range, into the larger 100 kWh version last August, extending it to 315 miles. But the Model 3's economical design has a smaller wheelbase, which won't fit the bigger power source, Elon Musk said. Neither he nor the company specified which size battery their new vehicle will ship with.