Launched in 1981, the “Electric car with high-energy battery” research project eventually led to eight BMW E30 325iX models being converted from all-wheel to front-wheel drive, ready for testing from 1987 onwards. They served as experimental vehicles, trialling a brand new, maintenance-free sodium-sulphur (NaS) battery, which had been purpose-developed by Asea Brown Boveri (ABB) for use in electric vehicles. With an energy density three times greater than that of conventional lead-acid batteries, it represented a great leap forward. 325iX was produced in 1986.
