Thrive, don’t just survive the winter in your EV!
There’s been a good amount of negative press about EVs recently, specifically about how the Polar Vortex contributed to range problems for many owners. It’s true that electric vehicles experience a reduction of their driving range in temperature extremes, both cold and hot. However, there are many steps that owners can take to maximize their range when the big freeze sets in.
I’ve been driving EVs since 2009, and have driven my EVs through ten New Jersey winters, so I have a little experience driving EVs in the cold.
***Note: Before someone from Saskatchewan, Canada, comments how “It doesn’t get cold in New Jersey!”, I’ll admit, Northern New Jersey doesn’t typically experience the same kind of winters as some regions of Canada do, but we do get a fair amount of snow and ice, and from December to March the temperatures are often well below the freezing point. These cold weather tips can be applied for EV owners in just about any cold-weather region.
There’s challenges to driving any car in the winter, but if you do drive an EV, here’s some tips that we feel will help you get the most out of your car when the deep freeze of the winter months set in.
Precondition: Just about every new EV sold today offers preconditioning features. Preconditioning allows the owner to heat or cool the battery and cabin as needed. You should use the precondition function as much as possible, preferably while connected to a 240-volt charging source. By using preconditioning to preheat the battery and passenger cabin, you’ll leave with a fully charged and heated battery, plus a warm cabin. Preconditioning allows you to use less of the stored energy in the battery for these functions, which will allow that energy to be used for its main purpose, to propel the vehicle.
You can set the preconditioning to begin every day at a set time, so your car is ready when you leave in the morning. Make sure the car is plugged in while you precondition, because you want to draw energy from the grid to do this, not drain down your battery. You’ll also want to be plugged into a 240v level 2 source, as preconditioning will draw more power than a level 1, 120v EVSE will deliver. If you don’t have a 240v charging source, the preconditioning procedure may need to dip into the stored energy in the battery, which isn’t ideal. In that case, the battery and cabin will be warm, but you may not depart with 100% state of charge.
Cabin Heat: Unlike ICE vehicles, there’s no waste heat from the combustion engine to heat the passenger cabin, so EVs need actual onboard heating systems. These systems are generally the biggest energy draw an EV will have, other than the propulsion motor. Maximizing your range will mean limiting the use of the cabin heater as much as possible.
Some EVs use a heat pump system which is more energy efficient than a resistive heater. The colder it gets, the less efficient heat pumps are, but they are still generally much more efficient than the resistive heaters found in most EVs.
However, even sophisticated heat pump systems still can use a fair amount of energy, and will indeed cut into the range. If your EV is equipped with heated seats and steering wheel we recommend using them as much as possible. By doing so, you can limit the use the cabin heater, less which saves energy as the heated seats use much less energy than cabin heater; heat pump or not.
If you simply dress a little warmer, and use the heated seats and steering wheel you can really cut down on the use of the cabin heater, and this will have a very positive effect on your range.
Properly Inflated Tires: This might be the most overlooked ways to increase your EVs range in the winter. As the temperature drops, the air in your tires contracts and the tire pressure falls, unless you’ve filled the tires with nitrogen. Tire experts say that for every 10 degrees of temperature drop your tires can lose 1-2 lbs of pressure. Under-inflated tires create more road friction which will reduce the vehicle’s efficiency.
Always make sure to check the recommended and maximum pressure for your tires, because it’s different for every tire and car. Be sure to check your tire pressure frequently during the winter, as temperatures can fluctuate greatly in short periods of time. Having properly inflated tires is an easy way to help maximize winter range.
Regenerative Braking: Using the regenerative braking system on your EV to maximize range is always a good idea. However, it can be an even bigger asset when you really need to squeeze out every mile of range possible. It’s also important to note that when the battery is very cold, the regenerative braking system will be less effective. Cold batteries can’t accept as much energy as warm batteries can.
Therefore, to minimize the possibility of damaging the cells, an EV will scale back the amount of energy it can recapture from regeneration. This will be particularly noticeable when you first get into an EV that’s been sitting in the cold for a while. If the battery is very cold, it may feel like there’s no regeneration occurring at all, so be prepared to use the friction brakes more than usual until the battery warms up a bit from use.
Park Inside Or in Direct Sunlight: Whenever possible park the car in garages, especially if they are heated. If you park outside for an extended period, like during work, try to find a spot that will be in direct sunlight. By parking in direct sunlight you’ll have a warmer cabin and battery when you return to your car. Every little bit helps, and direct sunlight is your friend, so use it!
Slow Down! Besides preconditioning and conservative use of the cabin heater, driving a little slower is perhaps the best way to extend your range. This is true regardless of the ambient temperature, but during the winter months driving a little slower can help offset the range you lose to the cold. If you do knock off a few miles per hour on the highway, make sure to move over into the right lane so you don’t hold up traffic.
If you can manage to cut 10 mph off your normal highway speed, you’ll be amazed at how much of a difference it will make to your range. Also, accelerate slowly when possible. Jack-rabbit off-the-line launches are definitely fun, but they also consume a lot of energy.
Charging Times Increase: Cold batteries won’t accept as much energy as warm ones will, so expect longer charge times. Also, if equipped, your car’s thermal management system may also be working to warm the batteries. The thermal management system takes some of the energy that would have gone directly into the battery, so that can extend the charge time also.
On really cold days I’ve noticed it takes my BMW i3 thirty to fourty-five minutes longer to fully charge. Knowing this, you may have to adjust the delayed charging setting if you use that, and allow for more time before you can unplug.
Also, the simple act of charging the car warms the battery. So you may want to use the charge timer on your car, or on your EVSE if you have a smart-charger like the eMotorWerks JuiceBox or Flo Home X5.
Use Eco Modes: Most EVs have a couple different driving modes, with one of the options called “eco mode” or something very similar. Every EV implements eco mode differently, but this mode generally reduces the amount of power supplied to the drive motor and energy consuming features like the cabin heater.
Another benefit to using the eco modes in the winter is that by reducing the power to the motor, the car accelerates slower, and helps to reduce the possibility of wheel spin. Therefore, even if range isn’t an issue, it’s probably a good idea to use eco mode whenever driving on ice or snow covered roads.
Stay Calm & Drive On
So don’t fear the Polar Vortex! Sure, it takes a little more preparation, but by taking some simple steps you can easily become a winter-warrior with your EV. It also helps that more and more longer range EVs are becoming available now, and any observed winter range loss becomes less critical than it is on a short range EV.