37 degrees in Northern CA - reduced battery range?

[GenZeJohn]

Unseasonably cold weather seems to have had an adverse impact on my range. Seems like charge gets used faster. I've taken to using the heater only until the cabin is comfortable, then turning it off until it gets uncomfortable again. My conservative driving habits are the same, but the range meter seems to drop faster in the cold. Thoughts?

 

[mtndrew1]

Reduced range in cold weather is to be expected and everyone experiences it.

Air is denser, HVAC use is increased, rolling resistance of tires is increased, accessory usage is higher (defoggers, mirror heaters, seat heaters, lights, wipers, etc.).

Your best bet is to program the HVAC timer so that the heat comes on before your drive and uses power from the wall for the initial heater load. You can also initiate HVAC from shore power with the UVO app. As my morning departure times are inconsistent I use this method to heat up the car before I get in it without affecting range.

I don't think your method of switching the heat on and off is doing you many favors. It's the first ramp of heat demand that takes all the power; maintaining a warm cabin does not tax the system very much. Seat and steering wheel heaters use trivial amounts of energy so using those combined with driver-only setting of the HVAC at a moderate temp (maybe 65 degrees on auto for your 37 degree ambient example) will keep things comfy while minimizing range loss.

 

[GizmoEV]

To add to what mtndrew1 posted above you can also just lower the temperature setting and use auto mode. This is likely to use less energy than the manual on/off cycle you are using. As mtndrew1 said, the initial warm up is what saps a significant amount of energy. You can see the power use by going to the EV menu, selecting the Energy Information, Electricity use. There you will see the drive power, climate power, and lighting/other power. It also shows the predicted range with and without climate control. If you watch the climate power from when you first start you will see that it can start out at several kW and after the car warms up it will diminish significantly. Lowering the temperature difference between inside and outside reduces the climate system energy use. That is where the heated steering wheel and heated seat help significantly.

I have noticed a significant decrease in predicted range too. We have been having temperatures in the 20s-40s as well. What I find, however, is that I can drive farther than the predicted range provided there isn't a stiff headwind or I'm driving fast (I usually drive 60mph on the freeway). You can see this in a couple of different ways. One is set a destination that is farther than your predicted useable range and begin driving. Note where the green and then red range bar ends on the right of the navigation display. As you drive you will likely see that the bars get longer. This is most easily see if your destination is just out range or if you have a way point near where the green or red part of the bar ends from the beginning. I see this most of the time when I'm on a long trip. Every time I reach my destination or charging point there is more range left than what was predicted at the start.

The other way you can see how accurate the range meter is is by charging to full, note the predicted range, reset one of the trip meters and then go for a long drive. At the end of the drive compare the difference of the original predicted range and range remaining with the actual trip. I usually find that I have driven farther than the loss of predicted range indicates.

 

[user 154]

On a 100-mile trip in the rain and cold we had yesterday between Cupertino and San Francisco, I saw about 0.7x at best of the range I've come to expect on a gentle summer day. A fast charge to 82% netted me about 60 miles to empty, at mostly 60mph freeway travel in the rain.