Electric BMW Moves from Concept to Reality
By: Keith Barry
Source: http://www.wired.com/autopia/2011/02/electric-bmw-moves-from-concept-to-reality/
BMW has officially gone electric.
When BMW released the Concept ActiveE last year, the debut of a production model was almost certain. That day has come, and 1,000 lucky drivers in the US, Europe and China are about to get their hands on electrified L-series coupes.
Like the Mini E before it, the BMW ActiveE is a consumer-driven field test that allows BMW to work out the kinks in short-term production models and get real-world feedback for future vehicles. In this case, both the BMW and the Mini are testing the waters for the eventual Megacity Vehicle (MCV), which BMW says they will launch as part of a brand new sub-brand in 2013.
BMW developed all of the technology behind the ActiveE in-house, fitting an entire electric drivetrain into the space freed up on an existing 1-series design after pulling out the gas-powered drivetrain. Modular liquid-cooled Lithium-ion cells from SB LiMotive are hidden where the gas tank and transmission once were and under the front cowl, and BMW says they can power the vehicle up to 100 miles. EPA estimates are more optimistic, and peg the range at up to 150 miles.
Impressive, especially considering that this is a test bed based on an existing car.
Recharging takes 16-20 hours from a standard 110-volt socket, while plugging into a 240-volt socket tops off 220v/30a circuit will fully charge the batteries in under 5 four to five hours. Drivers can get an extra 40 miles Drivers can travel 25km if they plug in for just an hour.
According to BMW, with a 50/50 weight balance the car offers the same driving dynamics as a standard L-series, except with a 125-kilowatt electric motor in the rear, 0 to 60 comes in around nine seconds and top speed is limited to 90 mph. It’s no Tesla, but we repeat, this is a testbed based on an existing car.
In addition to the in-house drivetrain, the ActiveE features a complete EV-friendly rewrite of stability control software, and may just teach a new style of driving to electric BMW owners. Unlike the Mini E, the ActiveE’s “gas” pedal has been designed to immediately disengage the electric motor when the driver slightly lets up on the accelerator, allowing the car to glide and save battery life.
When the driver takes his or her foot off the pedal completely, regenerative braking starts and the ActiveE begins to slow down. BMW claims that 75 percent of urban driving can be accomplished with only the accelerator, leaving the brakes for emergency stops.
The circuit board paint job serves as a rolling billboard for BMW’s EV development. That aside, there are very few visual cues to distinguish the ActiveE from an internal combustion engine-powered 1-series. “ActiveE” badges are visible, as is the silver blue trim that encloses the rear apron where the tailpipes have been omitted. The hood features a prominent bulge that provides more room for the electric drivetrain, and low rolling-resistance tires are fitted to lightweight 16-inch alloys. Inside, blue stitching contrasts against a gray interior.
Like with the Nissan Leaf, the car can be “preconditioned” — cooled or heated while plugged in — through an iPad or other device using BMW ConnectedDrive software. ConnectedDrive also estimates battery life and range, allows comparisons with ranges achieved by other ActiveE drivers and — most importantly for BMW — sends vehicle information back to the engineers in Munich.