[ad#post_ad]Recent snowfall gave me a chance to experience driving the MINI E electric car in snow and ice conditions, and the frigid northeast weather has been a test of its batteries.
I am leasing the MINI E for a one year period as a part of BMW’s field test trial, and am among 449 other drivers in California, New Jersey, and New York. At this point, after six months of driving, the car has just over 7700 miles.
There has been a pronounced decline in battery range in the cold weather. On a recent trip at a temperature of 23 degrees Fahrenheit and including a two-hour 110 volt charge in the middle, the battery meter hit zero miles/zero percent after just 55 miles (see graphic). The car is billed as having a 100 mile range.
According to a report in the Washington Post MINI E drivers are noticing about a 20% reduction in range in cold weather. A MINI E driver in New Jersey with an 85 mile commute found this out the hard way during a cold snap. “Towed! After only 87.8 miles…Sheesh!” he wrote in a blog post.
My commute is 60 miles round-trip, mostly highway and at about 60 to 65 MPH with accessory heat running. It isn’t clear if the battery charge level detection circuitry has become more inaccurate in the cold, whether the battery is aging and losing range, or if range is actually reduced in the cold. I suspect all three factors are in play with the latter being most important. In 65 degree weather, I can extrapolate roughly 75 to 80 miles of range on the same commuting cycle.
So in the cold weather even with a 2 hour charge at my office in the midpoint of my 27 mile each-way commute, I find myself regularly drving for the last several miles with the battery meter measuring zero miles and zero percent. It is disconcerting. There is also some noticeable power fade, though I dont push it much in that situation as you might imagine. After stopping the car and letting it rest though, I find the meter could come up to as high as 10 to 15 percent.
Now on to driving performance.
On mild slightly icy and snowy hills the car performs poorly.
The front wheel spins with minimal traction, and the car can barely be made to creep along only by taking the foot on and off the accelerator. On another more snowy higher incline, the car got stuck altogether and had to be turned around.
I believe the performance to be significantly poorer than an ICE car of the same size.
MINI recommends changing the car’s all-weather tires for specific winter tires, obviously recognizing the car’s poor performance metrics in this environment. I have not done that yet. Though the car is front wheel drive, part of the problem is the instantaneous torque and the rear-axle placed center of gravity due to the 500 pound lithium battery sitting over it.
In all fairness, the MINI E is really a test prototype or mule, and is not optimized. BMW says these learnings will go into future cars.
The Chevy Volt will of course be very well winter-tested before it gets into real drivers hands.
“We have a number of VOLTs being tested as we speak in Kapuskasing, Ontario,” notes Volt vehicle line director Tony Posawatz. “All Chevy VOLTs will have stabilitrak standard, which includes traction control.”
This entry was posted on Monday, December 28th, 2009 at 7:50 am and is filed under BEV. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.