Unlike the electric Chevy Volt, BMW's Mini E doesn't have a heater to keep the battery at optimum temperature when it gets cold outside—sounds like a minor problem, but it halves the Mini E's range. Eep. Testers of the Mini E have been finding that at 23 degrees F, the car only managed to eke out 55 miles to a charge, nearly half the advertised 100 miles. Even in more mild winters, like Washington, DC, the car gets 20% less range than in warmer climes. Disappointing, to say the least—we hope BMW works out this kink before the official roll-out.
Well, once they partner up with Rolls Royce maybe they can line the batteries in some nice furs to keep them warm.
Funny that the charging process does not warm the batteries. Do they cool down once the car is motoring around? Mark
All Li-Ion battery cars have issues with cold temps But this is the ultimate in poor journalism.. You can go to a blog post here and see that the range of 55 miles was quoted by one driver on one event. The owner also added 2 hours of 110 VAC charge, making the truth worse, but also the owner said "After stopping the car and letting it rest though, I find the meter could come up to as high as 10 to 15 percent." So the quoted range has high error bars for sure. The 20% reduction is derived from a Washington Post article here (you may need to sign up for access). If you don't want to bother reading it, it talks about how the infrastructure needs more build out to help with range anxiety and helping with longer range travel, something that isn't news at all. The Mini E uses air cooled battery packs and they equilibrate to ambient temps when the car isn't used for a long time. Other cars have heaters for the battery, and plug-ins like the Volt warm the battery pack while plugged in to keep capacity high. And BMW/MINI is learning. The BMW electric citi-car (I forget it's name) goes to water cooling for the batteries. Also, those that live in really cold climates will probably recognize this trick: When it's so cold that the car won't crank enough, short the battery for an instant. The internal heating caused by this warms the battery up enough to provide the amps required to start the car! The more things change, the more they remain the same.... Actuall, this gets me thinking that in extreme climates, the MINIe batteries are probably overcooled, and don't get warm enough! But issues like this are far from new. Back in the days of the EV1, the leasees pooled knowledge on how to extend range, and share where they could plug in to help with longer range trips. This information sharing went as far as to include info about how much range increase one could expect from elevation reductions! (FWIW, my Mom and I went to a wine tasting event in the hills above San Jose. We left her house with 110 mile expected range, were at the winery with 50 or so left, and got back to her house with 87 miles on the gauge! This was after a round trip of about 40 miles! Anyway, range estimations in electric cars are just that, and they are very use dependant.) All this isn't to say that the range reduction with temps isn't an issue. It is, but like most constraints, it can be better managed than the reporting indicates. The new Tesla S-whatever 4 door, is to be available with a 300 mile range battery pack. Even degraded (I don't know if it has active battery heating), it will still be more than enough for most. The technology keeps advancing, that's for sure. Matt