Video: How EVs Combat the Cold

EVs, like nearly all vehicles, are not fans of extremely cold weather. Videos and articles about the horrors of EVs losing range and charging slowly have made the rounds giving many pause when considering going electric for their next vehicle. The reality is less dramatic with two pieces of technology that help EVs battle frigid weather while also preparing the battery for charging regardless of the weather. They're heat pumps and battery preconditioning. 

Preconditioning

If an EV can schedule the warming or cooling of the cabin ahead of departure, it likely has the ability to precondition the battery. Getting a battery ready for the day by warming or cooling it via power from the grid can go a long way towards getting optimal performance out of an EV even in cold weather. 

Lithium-ion batteries have a peak operating range between about 60 Fahrenheit (15 Celsius) and 95 Fahrenheit (35 Celsius). Considering the wide variety of batteries on the market, the optimal operating temperatures will vary slightly. When a battery is preconditioned, it's placed within that optimal operating range and will deliver optimal performance. 

It's true that EVs will lose range in cold weather. When a battery pack is cold, it's being used to both power the electric motor(s) and warm itself up. It does all this while the electrolyte between the anode and the cathode has thickened due to the frigid temperatures. By warming the battery pack ahead of departure by using power from the grid, the pack can start the day without compensating for a thickened electrolyte slowing down ions. 

An additional form of preconditioning is to get the battery ready for DC fast charging. Regardless of the weather, a battery will charge quicker at its optimal charging temperature. Fortunately, most modern EVs are equipped with the ability to precondition ahead of charging. 

To ensure that an EV will prepare its battery before it reaches a DC fast-charging station, the driver should set the in-car navigation destination (or way-point) to a charging location. Make sure the vehicle recognizes that the location is a charging station. 

The only issue is that many drivers use third-party mapping software like Google Maps and Apple Maps. Unless those applications are baked into the vehicle (like Google Maps in GM, Volvo, and Polestar vehicles), using a third-party app to navigate to a charging station will not precondition the battery. For the sake of quicker charging speeds, use native in-car navigation at least while charging. 

Heat Pumps

EV motors are incredibly efficient compared to ICE (internal combustion engines). Where this is most evident is warming the cabin of a vehicle. ICE engines give off an enormous amount of heat as waste. Automakers use that wasted heat to warm up the cabin of a vehicle. EVs give off very little heat and because most of the energy pulled from the battery pack is used to propel the vehicle. 

Automakers came up with two solutions. There's the PTC system that uses a resistive element to create heat. Energy is pulled from the battery and run through resistance which creates heat which is pumped into the cabin. 
A more efficient system is a heat pump. It's 300% more efficient than the PTC because two-thirds of the energy used to heat the cabin is from ambient air and other sources of heat from the vehicle. Only one-third of the power used is from the battery pack. 

By using heat pumps automakers are able to heat the cabin of an EV more efficiently. That results in more range during winter months than only using the PTC system. 

As EVs continue to mature these systems will become more robust. Kia for example has an entire unit focused on heat pumps to make them as efficient as possible.