Do EV Chargers Take Longer to Charge When it’s Cold Out?

December 20, 2022
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How Cold Affects EV Chargers

Winter is almost officially here, which means having to deal with cold, snow and ice for at least a few months. While the Seattle area isn’t as cold or snowy as many other northern cities, the winter weather can still have an impact on your day-to-day life in numerous ways. This is especially true for those who own an electric vehicle as cold temperatures will affect both how long it takes your EV to charge and also its range. The impact isn’t that severe, but it is definitely still something that you need to be aware of to ensure that you and your EV are ready for winter.

Longer Charging Times

All EVs have a built-in control known as a Battery Management System (BMS) that dictates the rate at which their battery charges. Charging in cold temperatures puts extra stress on the battery, which could cause it to degrade more quickly. To protect the battery and ensure this doesn’t happen, the EV’s software automatically reduces the rate of charging whenever the temperature begins to drop. The colder the battery is, the slower its charge rate will be.

Inside your EV battery is a thermal management system that measures the battery temperature and sends this info to the BMS. If your battery is extremely cold when you first start charging it, the BMS will limit the charging speed to help protect the battery. As the battery charges, its temperature will continue to rise. Once the battery reaches the ideal charging temperature, the BMS will then begin to allow it to charge closer to its normal rate.

Studies have shown that the average EV will receive approximately 36% less charge at 32 degrees Fahrenheit than it would if charged for the same number of hours at 77 degrees. The impact isn’t all that noticeable on milder days, but the rate of charging quickly decreases once the temperature drops below 40 degrees.

This is important to remember as it means that you will need to leave your vehicle plugged in for a longer period of time the colder it gets. This factor may not impact your daily commute all that much, but it is definitely something to think about when planning longer trips.

Decreased Range

All EVs also have a decreased range in colder temperatures, but this is actually comparable to the impact that cold has on gas-powered vehicles as well. The average EV loses about 20% of its typical range in freezing conditions, while gas vehicles also have their fuel efficiency reduced by around 15 to 20%.

Part of this decrease has to do with the extra energy that it takes to run your vehicle’s heating system. In EVs, the decreased range is also due to the fact that the vehicle reserves some of its stored power to keep the battery warm. This is important because if the battery doesn’t stay warm, it will lose its charge far more quickly.

The good news is that cold temperatures won’t degrade your EV battery as long as you always keep it charged to at least 20%. As soon as the weather begins warming up again, your vehicle’s range will go back to normal. Now that you know how cold affects EV charging and range, let’s take a look at a few tips that can help to offset these effects.

Store and Charge Inside Whenever Possible

Keeping your vehicle stored in your garage is by far the best way to protect the battery during the winter and limit the effect that cold has on its range and charging rate. This is where home EV charging stations can be a huge help by enabling you to park your car in the garage and charge it overnight.

When heading out for the day, you should also always try to park in a parking structure or other enclosed space whenever possible. Even though parking garages usually aren’t all that warm, they are still warmer than parking outside. Parking inside will always help to keep your battery at least slightly warmer and reduce the impact that cold has on your EV’s range.

Always Warm Up Your Car Before Driving

One handy thing about EVs is that most come with an integrated app that allows you to remotely start the vehicle. This can be a huge benefit during the winter by easily enabling you to start your car and make sure it is warm before you set off on the road. This will obviously help in terms of your comfort, but it has an even bigger benefit by warming up your battery so that it is more efficient and has a better range. Even better is if you warm up your car while it is still plugged in as this will ensure that your battery has as much charge as possible.

Consider Using Seat and Steering Wheel Heaters

No matter what type of vehicle you have, running your heating system constantly uses lots of energy. Nonetheless, this problem is much more pronounced in EVs since gas-powered vehicles can rely on the heat produced by their engines to help keep warm.

If you use your heating system all the time in the winter, it will result in your EV’s battery draining much more quickly. Studies from AAA estimate that driving in temperatures of 20 degrees or less with your heating system on will reduce an EV’s range by approximately 41%. This means that if your vehicle’s normal range is 250 miles, you may not even get 150 miles if you were to drive with your heating on.

Once your vehicle is fully warmed up, it is always a good idea to turn the heating down or off and use your seat and steering wheel heaters to help you stay warm. The less you use your heating system, the slower your battery will drain. This will increase your vehicle’s range.

Always Maintain a Minimum of 20% Charge

You really should never let your EV battery drop below 20% charge any time of the year, but this is especially true during the winter. If your battery ever gets too cold, your vehicle will pull some of the stored charge to heat the battery. If this were to happen when the charge was below 20%, it could result in your battery dying before you get to your destination and leaving you stranded in the cold.

Upgrade to a Type 2 Charging Station

Type 1 EV charging is convenient since it means you can plug your vehicle into a normal outlet. The issue is that Type 1 charging is slower and can potentially take up to a full day for the battery to receive a full charge, even in warm weather. One of the easiest ways to overcome the slower charging speeds in cold temperatures is to have a Type 2 EV charging station installed at your home. With a Type 2 station, you should be able to ensure that your vehicle always fully charges overnight, even when the temperature outside is below freezing.

If you’re considering an EV charging station for your home, Brennan Electric is ready to help. Our licensed electricians install home EV chargers as well as whole-home surge protectors, hot tub wiring, RV plugins and whole-home generators. We can also help with any of your other electrical repair or installation needs. To learn more about the benefits of a home EV charger or if you need any electrical service in the Seattle area, contact Brennan Electric.

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