Chemistry
Solid state
Nothing all solid state is in a customer's car. Everything you have read about it is a roadmap.
At a glance
- The best real data point. Mercedes ran a lightly modified EQS test vehicle 1,205 km from Stuttgart to Malmo on one charge in late August 2025, using lithium metal cells from Fa
- Timeline. Mercedes' own framing is series production by the end of the decade.
- Semi solid is not solid state. NIO ships a semi solid pack in China and it is a weaker claim
- Verdict. Treat any consumer facing copy saying solid state is here as marketing.
What actually happened
Mercedes ran a lightly modified EQS test vehicle 1,205 km from Stuttgart to Malmo on one charge in late August 2025, using lithium metal cells from Factorial Energy, with 25 percent more usable energy in the same package and pneumatic actuators to manage cell swelling.
Everything else
Toyota's production approval, QuantumScape B samples in Volkswagen test cars, Nissan's 2028 target and the Honda and Factorial demo lines are all roadmap rather than product. Semi solid packs such as NIO's 150 kWh ship in China and are a different and weaker claim than solid state.
So should you wait
No. A battery you can buy in 2026 is a known quantity with a measurable state of health. A battery announced for the end of the decade is not a reason to keep a car you do not want.
Buying a Used EV or Hybrid?
Get the battery measured before you pay for it. A PPI Auto inspector tests the pack on the car you are looking at and sends you the numbers. Starting at $225.