Winter lowers the fuel economy of all cars, but the loss affects electric cars more than it does conventional cars. Most manufacturers do a poor job of telling customers how cold affects an EV battery, so many new electric car owners are surprised when their range drops 20% or more as the temperature outside decreases.
All batteries operate best within a certain temperature range. Their performance drops off sharply if they get too hot or too cold. All EV’s have thermal management systems to keep them cool in the summer and warm in the winter. The problem is, the system that keeps the battery warm when it is cold outside uses a lot of electrical power – power that can’t be used to move the car forward later.
To offset this energy loss, many EV owners pre-condition their cars while they are plugged in to the charger at home. The battery warmer is set to come on several hours before the car will be used used, so when it is time to go to work, the battery and the car’s interior are warm and toasty. Using electricity from the grid to get the car pre-heated will minimize range loss in the winter. Experienced EV owners know that a Level 1 AC charger won’t deliver enough electricity to warm the battery and charge the battery at the same time. Only a 240 volt Level 2 charger is capable of supplying enough electricity to do both.
Having the passenger cabin warmed up before you start driving will also reduce the need to use the heater. Some cars have advanced heat pump systems for warming the interior, but they still require a fair amount of power to operate, which reduces range.
Here’s a list of things an EV owner can do to minimize range loss in winter:
- Park inside in a heated garage whenever possible
- Park outside where sunshine will help keep the car warm during the day
- Keep your tires properly inflated — cold temperatures lower tire pressures, which increases friction and lowers range
- Dress warmly, wear hats and gloves and use the seat heater instead of the cabin heater
- Try driving a little more slowly on the highway. Reducing speed from 65 to 60 can boost range considerably
Tesla owners may not notice the drop in range as much as someone driving an EV with only 80 miles of range under ideal conditions, but all battery operated cars suffer a loss of range in the winter. Tesla owners in New England frequently see their range shrink to 200 miles or less. Pre-conditioning, dressing warmly, keeping tires properly inflated and driving a little slower can all help. The most important thing is to recognize that your EV will not have its maximum range in the winter and to plan recharging stops accordingly when travelling.
Car makers are reluctant to tell people their electric cars won’t be able to go as far in winter but they should. A well informed customer is a happy customer and nobody likes surprises. At least now you will know what to expect from your EV when temperatures drop as the seasons change.