MINI Cooper 2027: SVOLT semi-solid-state battery and possible range gains

© A. Krivonosov / SPEEDME

The electric MINI Cooper could stretch its range from today's 400 km to more than 500 km WLTP without any noticeable increase in battery size. The plan hinges on SVOLT’s semi-solid-state cells, which reach an energy density of 270–300 Wh/kg. BMW and MINI, however, still haven’t officially confirmed either the new battery or the final range of a production model.

SVOLT plans to begin mass production of its hybrid solid-liquid batteries in September 2026. The manufacturer claims their production cost will be comparable to conventional lithium-ion batteries, while safety should improve thanks to partially replacing the flammable liquid electrolyte with a solid one. Early reports linked supply for future MINI models to 2027.

Calling this battery fully solid-state isn’t accurate: a liquid electrolyte remains inside. SPEEDME.RU has previously explained the differences between LFP, NMC, sodium-ion and solid-state batteries. The main benefit of this in-between technology is the ability to store more energy at a comparable weight and perform better in cold temperatures.

The current Cooper E comes with a 36.6 kWh usable battery and covers up to 300 km, while the Cooper SE, with a 49.2 kWh pack, reaches up to 400 km WLTP. In Spain, the base electric model costs €29,810, while the SE version starts at €30,350.

The likely second recipient of the battery is the MINI Aceman, which uses a related platform and is also built by the BMW-Great Wall joint venture in China.

It’s too early for buyers to hold off on an order for the sake of the new battery. Its capacity, charging speed, longevity and effect on price remain unknown, and the MINI connection is based on industry reports rather than an official product announcement from BMW.