(January 4, 2010) After building and deploying nearly 600 battery powered MINI Es in 2009 for a real world field test, BMW is moving on to phase 2 of Project i. Project i is a program to develop new forms of urban transportation based around electric drive systems.

The next step involves building a BMW branded car around newer lithium ion battery technology developed specifically for automotive applications. The ActiveE concept that is to be unveiled at the 2010 North American International Auto Show is a prototype for the next test vehicle.

The ActiveE is a 1 series coupe that has had its internal combustion powertrain replaced with electric drive components. For the MINI E program, BMW went to California based AC Propulsion (ACP). ACP produced lithium ion battery packs that are similar in configuration to the Tesla Roadster. The 35 kWh packs consist of several thousand 18650 type cells of the same type used in laptop computers. ACP also produced the electric traction motors and power electronics for the MINI.

For the ActiveE, BMW is using a pack developed with SB LiMotive. SB LiMotive is the joint venture between Bosch and Samsung to build lithium ion batteries. BMW recently announced that it would be working with SB LiMotive on its future electric and hybrid vehicles. BMW has not revealed the capacity of the battery pack but does list the estimated range of the car at 150 miles based on the FTP72 driving cycle.  FTP72 is the basis of the EPA's urban driving mileage test. After MINI E lessees expressed some disappointment with the real world range of the earlier EV, BMW is now saying that the real world range will likely be about 100 miles. 

The new battery allows for much better packaging than in the MINI. The elimination of the drivetrain leaves the engine compartment and center tunnel of the rear wheel drive 1 series open. The battery pack now occupies the tunnel and lower part of the engine compartment. This allows the ActiveE to retain its four seat configuration unlike the MINI which was reduced to only two seats.

A 170 hp synchronous electric motor is mounted at the rear axle providing direct drive through a single speed reduction gearbox. The trunk capacity is reduced somewhat from 13.1 cubic feet to 7 cubic feet.

In spite of a simplified powertrain, the liquid cooled battery remains a significant portion of the overall mass of the ActiveE. The base 135i coupe weighs 3,373 pounds while the electric concept now weighs 3,900 pounds. Because of the bulk of batteries, automakers will have to focus on weight reduction in new dedicated electric vehicles.

In spite of the extra mass, it is well distributed down the center of the car and low in the chassis. This should help the handling by lowering the center of gravity. The torquey electric motor should allow acceleration to 60 mph in about 8.5 seconds.

BMW has promised a second real world test using the ActiveE although no timing has been revealed. Drivers of the ActiveE will be able to monitor and manage the charge state of the battery using a mobile phone application.