2012 Nissan Leaf winter testEnlarge Photo
The nights are getting longer, children are starting to get ready for Halloween, and in certain states, you’ll have already had the first fall frost.
If you’re approaching your first winter of plug-in car ownership, however, you might be in for a shock as the mercury starts to drop.
Like you, your plug-in car won’t want to travel as far per charge when it’s cold.
It isn’t a case of premature battery degradation, either.
Lithium-ion battery packs, like humans, have a pretty narrow band of tolerance to temperature. Like their drivers, plug-in car battery packs prefer to stay at room temperature for maximum efficiency.
The colder the batteries get, the less effective power they can deliver.
In order to help keep the batteries warm during really cold spells, many cars--like the 2012 Tesla Model S and 2013 Chevrolet Volt--use liquid battery conditioning, circulating warm fluid throughout the battery pack to keep it at peak operating temperature.
Whilst charging, electricity to power the battery pack heater comes from the charging station the car is connected to.
The Tesla Model S in winter testing.
The Tesla Model S in winter testing.Enlarge Photo
When in use, or parked up without being plugged into a charging station, electricity from the battery pack is used to keep itself warm.
Other cars, like the 2012 Nissan Leaf, use a battery heater mat, which turns on at low temperatures to prevent the battery pack from getting too cold. Similar to the liquid heating system, it also uses energy from the battery pack when not plugged into a charging station.
More energy used to keep the battery pack warm means less energy is available to move the car along, reducing range.
In reality however, it isn’t the battery pack warming which reduces your range: it’s keeping YOU warm.
In cars like the 2012 Nissan Leaf, running the heater on a cold day--even if you’ve pre-warmed the cabin using electricity from a charging station--can reduce your car’s range by as much as 20 miles.
It’s a problem that automakers are already working hard to solve, with many next-generation cars expected to use more energy-efficient heat pumps to keep occupants warm instead of old-fashioned resistive heaters.
To help you and your plug-in car survive the colder temperatures that fall and then winter bring, here are some simple tips to follow.
winter driving - by flickr user Hey Paul
winter driving - by flickr user Hey PaulEnlarge Photo
Are you approaching your second winter of plug-in ownership? How do you keep yourself and your car warm in the winter months?
Share your tips in the Comments below.