Count me among the many thousands of Washington area residents who spent Wednesday night stuck in traffic as a snowstorm sowed chaos all around us. Being car-bound in sub-freezing weather for six hours can make a guy think. I counted my blessings. The situation could have been worse, I realized: My fellow commuters and I could have been trying to make it home in electric cars, like the ones President Obama is constantly promoting, most recently in his State of the Union address.
It is a basic fact of physical science that batteries run down more quickly in cold weather than they do in warm weather, and the batteries employed by vehicles such as the Nissan Leaf or the Chevy Volt are no exception.
The exact loss of power these cars would suffer is a matter of debate, partly because no one has much real-world experience to draw on. But there would be some loss. Running the heater to stay warm, or the car radio to stay informed, would drain the battery further.
Here’s how thecarelectric.com, a pro-electric Web site, candidly summarized the matter:
“All batteries deliver their power via a chemical reaction inside the battery that releases electrons. When the temperature drops the chemical reactions happen more slowly and the battery cannot produce the same current that it can at room temperature. A change of ten degrees can sap 50% of a battery’s output. In some situations the chemical reactions will happen so slowly and give so little power that the battery will appear to be dead when in fact if it is warmed up it will go right back to normal output. . . .
“In a car where all power is supplied by a battery pack you can see where this would be a problem. The batteries don’t produce as much power so the car has less power. The batteries also have to work harder so the effective range of the car is also significantly reduced. Charge time will also be longer. Cold has a negative impact on all aspects of battery operation.”
“Alongside the negative impact on the batteries cold also has a negative impact on the driver as well. Drivers need to be warm to operate the vehicle effectively so on top of the reduced range and power of the batteries just from the temperature they also must operate the car heater to keep you warm. This will further reduce the range of the car.
“If you live in an area where the winters get extremely cold an all-electric vehicle will have to be garaged and equipped with some kind of plug-in battery warmer for it to be effective in the coldest months of the year. Keep these thoughts in mind if you’re planning an electric car purchase; we don’t want you finding out the range of your car has been halved when it’s five below zero and you’re fifteen miles from home.”…