Fisker has abandoned plans to develop an advanced solid-state battery to use in its future production vehicles.

The car manufacturer has been working on solid-state batteries for a number of years and in 2018, stated that its (since-abandoned) EMotion sedan would soon hit the market with a solid-state battery pack. Evidently, perfecting the technology has proven to be too difficult.

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“It’s the kind of technology where, when you feel like you’re 90 percent there, you’re almost there, until you realize the last 10 percent is much more difficult than the first 90,” Henrik Fisker recently told The Verge. “So we have completely dropped solid-state batteries at this point in time because we just don’t see it materializing.”

“So, as we got toward the end of this — or let’s put it, as we got close to understanding fully this technology, we realized that it was much more difficult than we had predicted and expected in the beginning as we were very excited about some of the early things we were doing.”

According to Henrik Fisker, the company decided in late 2019 or early 2020 that solid-state batteries “are still very, very far out,” suggesting that they could be at least seven years away from reaching high-volume production.

Since scrapping the EMotion and its plan for solid-state batteries, Fisker has pivoted its focus towards the $37,500 Ocean SUV that will use a lithium-ion battery pack. The company is also in the early stages of developing a new affordable model that it believes could revolutionize the EV industry.