The 2020 Chevy Bolt undergoes a few critical changes and tweaks for the new model year. 
Said changes help the new Bolt return an EPA-estimated 259 miles of range on a full charge.

Change in the interest of range: that’s the story behind the 2020 Chevy Bolt EV due later this year. Chevy recently announced EPA ratings for the new Bolt, a praiseworthy 259 miles of range on a single charge. The figure, a 21-mile increase versus the current Bolt, addresses the nagging concern of range anxiety potential buyers have when considering an EV. According to AAA, 20 percent ? or close to 50 million Americans are looking to buy an electric vehicle as their next car. The figure represents a 15 percent jump from 2017.
?At Chevrolet we?re constantly listening to customer feedback and we heard the desire for more range,” explained Tim Grewe, director of Global Battery Cell Engineering and Strategy. “The team worked diligently to find ways to improve battery energy, giving customers the confidence to go more than the extra mile.? 2020 Chevy Bolt: Cell Chemistry Changes
The battery engineering team spent the bulk of their time improving the energy of the cell electrodes. While it sounds like a Herculean task, Chevy says it was more about little tweaks versus moving mountains. The automaker describes these changes to the Bolt’s cell chemistry as small but impactful. While they don’t elaborate beyond that, Chevy says packaging is unaffected by the changes. Eve...