DETROIT (AP) — A small battery company backed by General Motors is working on breakthrough technology that could power an electric car 100 or even 200 miles on a single charge in the next two-to-four years, GM’s CEO said Thursday.

Speaking at an employee meeting, CEO Dan Akerson said the company, Newark, Calif.-based Envia Systems, has made a huge breakthrough in the amount of energy a lithium-ion battery can hold. GM is sure that the battery will be able to take a car 100 miles within a couple of years, he said. It could be double that with some luck, he said.