On July 25, BMW’s first dedicated i Store opened its doors at London’s Park Lane, right next to the BMW and Mini dealerships, a year and a half before the i3 premium city car rolls off the production line at the company’s Leipzig plant.
The i3 was previewed by a concept study at last year’s Frankfurt Motor Show. The prototype is powered by a 170HP electric motor, although BMW has revealed that the production model will also feature a range-extending gasoline engine that will work as a battery generator.
That much you may know as the Munich-based automaker has been promoting its i sub-brand heavily, the most recent example being the i3 Coupe, a three-door version of the 2011 study.
What may come as a surprise to some is that BMW has been working on electric mobility for nigh-on 40 years. Although the 1972 Olympic Games that were held in Munich will remain in history for the tragic events that occurred, it was also the starting point for BMW’s development of electric vehicles, a brief account of which follows below.
BMW 1602 Electric (1972) / LS Electric (1975)
It all started in 1969 when BMW chose the successful 02 Series to begin research on the suitability of an electric drive for everyday cars.
The electric drive consisted of a Bosch-developed shunt-wound motor with a maximum output of 32 kW (43HP) and 12 standard 12V lead-acid Varta batteries placed on a pallet. At 350 kg, the battery pack was quite heavy, but it could be replaced by a freshly charged one, while even back then, the electric motor also worked as a battery generator.
The two prototype 1602 Electric cars that were built were used as support vehicles during the Olympics, though, it was clear that the limited range (30 km/19 miles) in city traffic, among other things, made them a first attempt rather than a feasible solution.
In June 1975, BMW made the second step towards electro mobility, though, it chose to keep it a secret at that time: it took a discarded LS and created a new experimental electric vehicle.
The 1602’s shunt-wound motor was replaced by a new DC series motor, again developed by Bosch, and the battery pack consisted of 10 Varta lead-acid batteries with centralized water topping and degassing.
The experimental LS was the first vehicle with a charger and leads that allowed the batteries to be recharged by a standard socket in 14 hours.
BMW 325iX (1987-1990)
In 1981, BMW launched the “electric car with high-energy battery” project that resulted in eight 325iX cars being used to test a brand-new, maintenance-free sodium-sulphur battery developed by Asea Brown Boveri for use in electric vehicles.
This battery had an energy density three times greater than that of lead-acid ones and, for the first time, the increased weight and other drawbacks of EVs looked like they could be mitigated.
The eight experimental BMWs were converted from all- to front-wheel drive. A new feature was an electronic drive management for monitoring and regulating the battery pack’s charging, which was placed next to the electric motor.
BMW’s R&D department decided to test those prototypes in the real world. Thus, a 3-Series Touring was used by the German postal service as a delivery vehicle, while other cars where provided to state and local authorities.
BMW E1 & E2 (1991-1993)
The new sodium-sulphur batteries showed much promise, so research continued. Instead of modifying an existing vehicle, however, BMW Technik GmbH was ordered to develop an electric vehicle from the ground up.
Ten months later, the compact BMW E1 concept was displayed at the 1991 Frankfurt Motor Show and a version developed for the U.S. market, named E2, was launched at next year’s LA Show. Keeping weight down was crucial, so the body was built from extruded aluminum sections and the outer skin from recyclable plastic, with the hood and the boot lid made out of aluminum.
The battery pack was placed under the rear seats and the in-house developed electric motor was integrated, along with the transmission, in the rear axle. Charging times went down to just six hours from a mains socket and two hours from a special station, while range was up to 160 km (100 miles).
In 1993, an improved variant of the E1 was launched at Frankfurt, featuring the “ZEBRA” sodium-nickel chloride batteries that improved driving range and performance.
BMW 325 / BMW electric (1992-1997)
By the early 1990s, BMW was really pursuing electro mobility. The E36 3-Series was the basis for 25 experimental vehicles. Eight of those cars took part in the world’s largest public field trial that had the backing of the German Federal Ministry of Research and Technology, while six joined the Bavarian State Government fleet.
Issues with the sodium-sulphur batteries forced BMW to replace them with sodium-nickel chloride units from the E1 concept. During the project’s development, electric motor output reached 45 kW (60HP) and quick charging allowed a 75 percent battery charge to be attained in just 40 minutes.
MINI E (2008-)
By the end of the 21st century’s first decade, BMW had made strides in its EV research. Thus, no less than 600 (!) all-electric Mini E cars were provided to selected customers, both private and corporate, first in the U.S. and later in Europe.
The powertrain consisted of a 150 kW (200HP) asynchronous electric motor and a 35 kWh lithium-ion battery pack. It was good enough for a 8.5-second 0-100 km/h (0-62 mph) sprint and a range of 250 km (155 miles) and the data gathered from everyday use were channeled into the development of what was at the time known as the BMW Megacity Vehicle.
BMW ActiveE (2010-)
Nearly a year after the Mini E test fleet commenced testing, BMW unveiled the Concept ActiveE prototype. Based on the 1-Series Coupe, it was created to test pre-production versions of the components that would make it in the Megacity city car.
More than 1,000 test vehicles were built, powered by a 125 kW (167HP), 250 Nm (184 lb-ft) electric motor. The newly-developed lithium-ion battery provided a range of nearly 160 km (100 miles) in everyday use and all components, which were developed in-house, were designed so as not to compromise interior space.
By Andrew Tsaousis
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