How will a hybrid electric vehicle electric drive perform in severe frost?

Question

Every description of hybrid electric vehicles goes to lengths explaining how good it is that an electric motor can be used in cases where the internal combustion engine is not very efficient and thus save fuel and lower the environmental impact.

Now what happens if it's −25 Celsius (appr. −13 Fahrenheit) outside? Such temperatures are not that uncommon - there're cities with population over 10 million in areas where such temperatures persist for months. AFAIK batteries discharge waaaay faster at such temperatures.

Will the battery in a hybrid electric vehicle still perform well in severe frost or will the vehicle just run as plain old internal combustion engine vehicle?

Answer 1

It depends on what you mean by "hybrid electric vehicle." A car with a "series hybrid" drivetrain like the Chevrolet Volt always uses its electric motor, even when its gasoline engine is running to charge the battery. A "parallel hybrid" drivetrain like that used in the Honda Insight uses the combustion engine most of the time anyway; its electric motor mostly helps with accelerating (e.g., starting from a stop).

Since cold weather effectively reduces the battery's capacity, it will need to be recharged more often (e.g., more time running the combustion engine in a Volt or other series hybrid, shorter range in a battery-only car like the Nissan Leaf). Or, it will have less extra accelerating power available to help the combustion engine. Either way, the efficiency gain from having the electric motor will be reduced, perhaps severely. It's hard to say exactly how severely because there are so many other factors in play.

You might check out this Washington Post article to read more.

In no case, however, will the car completely "abandon" its electric motor and run on combustion only, unless the batteries are damaged.