In your first winter, you may notice 30 percent or more decrease in your electric driving range. That can be a shock to hear from the dealership that, yeah, your car’s just fine. But cold weather range loss, it’s totally normal. Most EVs, when the temperatures dip between 20°F and 32°F, will lose between 22 and 25 percent of their range, and up to 40 percent if the resistive cabin heater is turned on at full blast. But it’s only temporary, it doesn’t hurt the battery packs.
Cold temps mean extra requirements as an EV heats its cabin (using energy from its traction battery) and heats its liquid electrolyte to keep it liquid. While battery chemistry becomes sluggish in cold weather, cabin heating is the main loss of range. Drivers can minimize wasteful energy draw by adjusting for smarter cabin heating, charging, driving and parking. Here are six ways you can make the most of your battery’s energy during winter driving.
1. Precondition the Cabin and Battery While Plugged In
Pre-conditioning your vehicle when plugged into a home charger is one of the best winter range savers around. You can use your car’s smartphone app to set what time you’re leaving and the heating will warm the cabin and battery pack before your trip. Since the heat is coming straight from the grid, the car won’t have to draw as much from the battery pack for an initial warm-up. This saves a lot of the high-voltage battery capacity for the ride rather than for heating an ice-cold EV.
Preconditioning Benefits:
- Warm the cabin before departure
- Heat the battery using grid electricity
- Preserve stored driving energy
- Gain roughly 10-15% usable range
- Reduce cold-start energy consumption
According to independent winter range testing, preconditioning delivers about 10-15 percent more usable range in the cold on a freezing morning versus rolling out of the driveway in a vehicle left outside all night. A battery that’s warm at the start of the drive has a lower internal resistance and better ionic conductivity meaning it’ll perform better when you hit the road, with less sluggishness at the start and less of a jolt of energy needed to melt the ice in the windshield. Preconditioning the cabin and battery means starting your day with a ready-to-go temp and more remaining capacity to work with on the road.
2. Rely on Heated Seats and Steering Wheels
In the winter months, turning down the main cabin climate control, and using heated seats and steering wheel instead, can help curb your electricity use. Standard electric resistance cabin heaters use 3,000 to 6,000 watts of power to heat the airflow in a vehicle’s cabin. To put this in perspective, a heated seat and wheel combination draw about 50 to 75 watts each. Overall, localized heating is a far more efficient means of being cozy while you stay warm especially if you change your heated-habits.
Localized Heating Advantages:
- Heated seats use 50-75 watts
- Cabin heaters consume 3,000-6,000 watts
- Reduce primary HVAC usage
- Preserve valuable driving range
- Avoid unnecessary cabin heating
A high-capacity resistive heater can use enough electricity in a few hours to shrink the driving range by 40 to 50 miles. Also, you might want to be careful about turning on your windshield defroster. When you turn on the defroster, the air recirculation function turns off so your car has to pull in outside air to the interior and heat it, and that could be 5,000 to 7,000 watts. Localised heating is better whenever possible but if you need defrosting to keep your windows clear and be safe, then go for it!
3. Cap Daily Charging Between 80 and 90 Percent
Charging to 100% every day is tempting as an idea to get ready for winter range loss, but it’s not the most efficient over time. About 80 to 90 percent charge every day can actually be better. When a lithium-ion battery reaches full charge, the system disables or severely curtails regenerative braking, which is the process of putting energy back into the cells by gently braking or coasting. This is especially critical to know when driving in winter, as it can help make up for the added energy that cold causes.
Daily Charging Recommendations:
- Maintain an 80-90% charge level
- Avoid unnecessary full daily charging
- Preserve regenerative braking capacity
- Recover energy during deceleration
- Protect battery health and efficiency
If you don’t have enough headroom for your regenerative braking, you can’t recover as much energy while driving and braking uphill or at each stop. That energy gets converted into heat and goes through the mechanical brakes. If the battery remains between 80 and 90 percent capacity, you’ve got extra room to recover watt-hours whenever you slow down, and you’re within the range of the manufacturer’s guidance on optimal cell operation. With enough charging headroom, you can recover energy while you go while protecting the health of your battery during your daily commute in the cold.
4. Precondition En Route to DC Fast Chargers
Meanwhile, cold-weather road trips bring added complexity for electric vehicles that need a public DC fast charger. Plunging temperatures cause the lithium-ion cell to go into deep a deep “cold soak,” and putting a lithium-ion battery that has been chills into a high power charging station can cut charging speeds by almost a third. The battery management system controls how much power it allows in to prevent a process called lithium plating a damaging electrochemical phenomenon where metallic lithium deposits on the anode during fast charging at less than freezing temperatures.
DC Fast-Charging Preparation:
- Warm the battery before arrival
- Use the vehicle’s navigation system
- Prevent lithium plating risks
- Avoid nearly threefold charging slowdowns
- Reach peak charging speeds sooner
A handful of the latest electric vehicles from Tesla, Ford, Rivian, Hyundai, Kia, and General Motors can detect DC fast-charging locations and directions via their onboard navigation systems. When you select a charging location, the vehicle will begin warming its battery as it heads to the station. When the car arrives at the stall, the battery will be in a much more suitable state to accept the maximum charging power. Absent that preconditioning, the car will have to use some of the charging capacity to heat the battery before you can get back to the anticipated charging time.
5. Maintain Door-Jamb Tire Pressures Diligently
Cold temperature winter driving also lowers the inflation pressure of your tires and can increase rolling resistance another culprit for range loss. The leading cause of range loss during winter months is caused by temperature affecting the pressure of the tires. Every 10° F. of ambient temperature is the equivalent of losing 1 PSI of air in the tires which then causes increased rolling drag on cold pavement, consuming even more energy from the electric motors, further diminishing range another 3 to 7% beyond seasonal factors.
Winter Tire Pressure Tips:
- Check pressure when tires are cold
- Expect 1 PSI loss per 10°F
- Follow driver-side door-jamb specifications
- Avoid additional rolling resistance
- Protect range and tire wear
The driver needs a digital tire pressure gauge that checks the cold tire when inflating. The proper pressure reading is available on the sticker inside the driver side door jamb. Judging warm tires or guessing the amount of pressure by look is a common mistake, if the power level remains at a higher level and the tires are underinflated, your range will be lower. Correct tire pressure reduces resistance to increase power for the electric motors and provides correct contact and traction along with good treadwear while traveling along slushy and freezing roadways.
6. Park in Enclosed Garages or Direct Sunlight
The location of a vehicle when parked for the night may affect the amount of battery energy you use to prepare for a winter trip. Parking your electric vehicle in an enclosed garage, though, helps eliminate the effects of extremely low overnight temperatures, as well as a freezing wind that can apply during the night to a vehicle stored outside. To best maintain your battery, start your day about 20°F warmer.
Smarter Winter Parking Habits:
- Prefer enclosed garage parking
- Protect the battery from cold winds
- Start with a warmer battery
- Park facing direct sunlight
- Use natural cabin warmth
When garage or covered parking is not an option, sunlight can provide a free boost to warming a car at rest. An unshaded parking spot with direct sunlight on the vehicle, out the front windshield and side windows will help the warmth accumulated on the interior of the car stay warmer. This can result in the low string temperature being above freezing to help save a lot of energy used by resistive and heat pump systems on waking up. The best over night parking position is sealed off storage or catching the sunlight.
