Electrical automobile battery startup QuantumScape mentioned Tuesday that it has begun delivery prototypes of its batteries to automotive prospects, a key milestone  that it had aimed to hit by year-end.

The corporate’s shares rose in premarket buying and selling instantly following the information.

QuantumScape mentioned it has begun delivery “A0” samples of its battery cells to its automaker shoppers. These samples are almost full-size prototypes that may permit the automakers to check and start the method of validating the corporate’s expertise for automotive use.

QuantumScape did not identify the automakers receiving prototypes, however German auto large Volkswagen is a longtime investor within the firm.

The information that QuantumScape is delivery prototypes is a crucial milestone for the startup, however precise business manufacturing remains to be a minimum of just a few years away.

QuantumScape has been working for a number of years to develop a viable “solid-state” battery for electrical autos. Strong-state batteries are so referred to as as a result of they do not want the liquid or gel electrolyte discovered inside present batteries. A solid-state battery pack will be smaller and lighter than a lithium-ion pack of comparable capability, with a lot much less threat of catching hearth.

The expertise holds a lot promise for EVs, however researchers have struggled for years to make a solid-state battery that may maintain up over years of recharging. QuantumScape has developed an modern element – a battery “separator” product of a proprietary versatile ceramic materials – that, in lab exams, has given its batteries the flexibility to outlive greater than 800 charging cycles.

That is in regards to the quantity that an EV’s battery pack could be anticipated to endure over its lifetime – however scaling up that expertise from the laboratory bench to one thing usable in an EV has been a sluggish course of. Even after immediately’s milestone, the corporate is not anticipated to ship production-ready prototypes to its shoppers earlier than 2025.

“Whereas this milestone brings us nearer to our final purpose, there’s nonetheless rather a lot to do earlier than this expertise turns into a business product, and we now flip our consideration to this vital work,” CEO Jagdeep Singh mentioned in a press release on Tuesday.

By Monday’s shut, QuantumScape’s shares have been down over 73% in 2022.