Winter battery health

It's no secret that cold weather has an effect on battery health. Just think of your laptop or phone battery during the wintery months. You may or may not notice a drop in battery life. We certainly do- but what are the reasons for that?

Weather

Batteries have a love/hate relationship with the cold. On one hand they definitely don't like very hot temperatures, and on the other hand, performance may suffer in cold weather. One of the basic reasons is the battery will be working extra on keeping the car heated. Compared to internal combustion engines (ICE), electric vehicles don't produce as much wasted heating, so they need to provide it somehow for the passengers on those cold days in the car. Extra heat for the passengers means more power is necessary. The exact numbers may vary, but it's safe to say performance can be affected by heating alone by anywhere from 10%-50%, with the average likely somewhere in the middle. Temperature does have an effect on this of course, with negative-20 degrees Celsius and below having a greater impact. So if you're in a very cold climate you may see some obvious battery performance issues. However, if you are in a place that stays around 0 degrees Celsius to 15 degrees, the performance may not be as noticeable.

Regenerative Breaking

Another major battery performance limitation is regenerative braking in cold conditions. Regenerative braking, for those who don't know, is when the EV uses the heat generated from braking as energy reconverted to battery power. So while a traditional gasoline or diesel engine vehicle will brake and the heat will dissipate, EV's have the advantage of using the heat acquired from braking (kinetic energy) to help power the battery. However, in cold weather regenerative braking is affected. Less energy is able to be regenerated based off of the outside temperature, and more importantly, the battery temperature. If you have a short drive in a cold climate, which wouldn't give the battery sufficient warm-up time, you could experience poor battery performance.

Compounding these two factors together, the electrochemical reactions that take place inside a battery are slowed by cold temperatures. With this being said, we are naturally led to the question: how can we optimize battery health?

Optimizing

For starters, if you have a heated garage, then that's excellent. If you have a garage that's not heated, use it because it's still better than being directly outside. Keeping your car plugged in is a must when possible. Autel's AC MaxiCharger has Health Charging mode to prevent overcharge and increase battery safety, and the EV's themselves will also have onboard electronic protection so you can be rest assured staying plugged in is OK. The EV's will use a small amount of electricity to keep the battery warm. This way, when you're ready to depart you won't experience the potential loss of energy by heating the battery. Many cars come equipped with something called "pre-conditioning." You can set your departing time in the car's APP, and a short while before you leave, the car will draw electricity to heat up the interior to a desired temperature. This way you won't need to start from cold while on the road, and the electricity you pulled from was from the grid and not your EV's battery. Driving in an optimal way is also something to keep in mind. This includes avoiding quick acceleration and braking, and aiming to coast more often when possible.

Heat Pump

The last thing we'll mention in this article is a heat pump which is used by some EV manufacturers. A heat pump is not a new invention. It is actually the inverse of how a refrigerator works. Simply put, the job of the heat pump is to use the heat generated from cooling off the battery and distribute it throughout the EV. This feature can cost extra money for some EV models, and would likely not be as necessary in a warm environment. But for those who deal with normal cold temperatures it could offer a battery saving boost. The exact amount is hard to say as every EV manufacturer's technology and efficiency is different, but if it's worth mentioning here, then it's worth looking in to.

If you're living in extremely cold climates, it's probably not beneficial for you to buy an EV until the technology can deal with the extreme cold. However, for those who have four seasons or generally chilly temperatures, EV's are still great choices as modes of transportation. Maximizing your battery health in winter is like choosing your winter clothes. It's always best to be prepared.