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Cold Temperature Range Loss (Is it heat)?
- Thread starter pschall
- Start date
Brando
Active Member
YES - heating passenger & batteries - depending how cold - wear a coat/sweater to help set heating temp. down.
Heating is one important part for sure. Other factors include denser air to push through when it's colder, and that gets worse as you go faster. You can add higher tire resistance if you run winter tires when compared to low rolling resistance summer tires.
Driving on wet roads augments consumption, but that can happen in summer too. Driving in snow is even worse. You can see all the factors that affect consumption by playing around with the advanced settings of ABetterRoutePlanner.
Driving on wet roads augments consumption, but that can happen in summer too. Driving in snow is even worse. You can see all the factors that affect consumption by playing around with the advanced settings of ABetterRoutePlanner.
Those other factors have some impact, but based on my experience and reading on this subject, the vast proportion of lowered range in the cold is due to the energy used to heat the car. Newer models with heat pumps perform better on that score. That said, my 2020 Model 3, without a heat pump, does not suffer as much range loss in cold weather as I expected. Strategies can be used to minimize loss, such as pre-heating the battery and cabin before trips and using the seat warmers together with only moderate ambient heat in the cabin. The issue tends to be at its worst on days where you are doing lots of short trips in cold weather away from your home charger, since you are using battery-supplied energy to get the battery and cabin back up to operational temperature for each trip. Getting things back up to temperature takes a lot more energy than maintaining temperature. But days like that tend to involve local driving where range is not much of an issue in any event since you are not ultimately going very far.
loanchau2k
Member
Not only the heater uses your battery, but also other factors such as air pressure (drag down your car), electron flow resistant from anode to cathode. So, EV is not very friendly with cold weather 
I thought the primary reason for range loss in winter was the cold temperature...
For example if you charge the battery to 90% and leave it outside in a very cold temperature -25C (-13F) for let's say one night will the S.O.C stay at 90%?
Probably not even if you didn't drive or use any heating. The reason is because the chemistry in the battery cannot work very well in cold weather.
But yes add the heating, cold air drag etc in the equation and you get significant lower range. Please guys correct me if i'm wrong.
For example if you charge the battery to 90% and leave it outside in a very cold temperature -25C (-13F) for let's say one night will the S.O.C stay at 90%?
Probably not even if you didn't drive or use any heating. The reason is because the chemistry in the battery cannot work very well in cold weather.
But yes add the heating, cold air drag etc in the equation and you get significant lower range. Please guys correct me if i'm wrong.
SOC display will go down if you let the battery cool a lot, like to -25C. That's not range loss, it's a portion of energy that's temporarily unavailable (your chemistry argument). As the battery heats up you should regain that energy.
Using the car in very cold temperature uses up more energy in various ways. Heating the inside of the car is the obvious one, as is pushing against denser air, the faster you go the worst it gets. For heating, short drives will appear worst as you spent a ton of energy heating the cabin for just 5 minutes. The heating part is a bit better with a heat pump.
Then there are other aspects, like using winter tires that have a worst rolling resistance, or driving in rain or snow that augment rolling resistance.
Using the car in very cold temperature uses up more energy in various ways. Heating the inside of the car is the obvious one, as is pushing against denser air, the faster you go the worst it gets. For heating, short drives will appear worst as you spent a ton of energy heating the cabin for just 5 minutes. The heating part is a bit better with a heat pump.
Then there are other aspects, like using winter tires that have a worst rolling resistance, or driving in rain or snow that augment rolling resistance.
But the biggest drain is heat - heating both the battery to get it to a higher operating temperature (to overcome the temporary unavailability of stored energy in the battery due to the cold) and heating the cabin for human comfort. I expect that the drain to heat up the battery - adding heat to a big hunk of cold-soaked metal - takes up more of the energy than cabin heating, but I do not know that for sure. Both these sources of battery drain can be minimized by pre-heating the battery and cabin while plugged in just prior to your trip, because in deep cold it takes much less energy to maintain the battery and cabin at an appropriate temperature than to get them there in the first place. On the other hand, energy loss will be compounded if you are doing a lot of short trips without the ability to pre-heat while plugged-in while away from your home-base or other charging source before each trip.
Heating the battery can take a lot of energy, but the car will not do it when you drive. When driving, the only heat the car generates is for cabin heating. With the octovalve and heatpump the car can actually steal heat from the battery and use it for the cabin but I don't think it happens the other way around. It will only heat the battery in a couple of specific cases:
- You preheat the cabin. If the battery is under something like 10C, it will be heated during this cabin heating phase only. A Dual Motor can consume 6-7kW, a single motor ~3.5kW. If you are plugged in at home, if your SOC goes below the threshold it will charge at the same time to keep the set %.
- You navigate to a supercharger. The target temperature in this case is much higher.
I've heard of cases of extreme cold where the car might generate a bit of heat to protect the battery... I'm not sure that really happens. Why would they recommend you not leave it under -30C for more than 24h if the car was capable of warming the pack in that situation...?
EDIT: When you drive, waste heat produced in the motors for moving the car will be circulated in the battery... but the car will not spend additional energy to generate heat for that purpose.
- You preheat the cabin. If the battery is under something like 10C, it will be heated during this cabin heating phase only. A Dual Motor can consume 6-7kW, a single motor ~3.5kW. If you are plugged in at home, if your SOC goes below the threshold it will charge at the same time to keep the set %.
- You navigate to a supercharger. The target temperature in this case is much higher.
I've heard of cases of extreme cold where the car might generate a bit of heat to protect the battery... I'm not sure that really happens. Why would they recommend you not leave it under -30C for more than 24h if the car was capable of warming the pack in that situation...?
EDIT: When you drive, waste heat produced in the motors for moving the car will be circulated in the battery... but the car will not spend additional energy to generate heat for that purpose.
The other battery drainer is those rear view mirrors hanging out there on a five or six hour autopilot Cruise. Can't tell you exactly how much that'll extend your range and I don't think anyone at Tesla knows? My overall vehicle calculations come to about {two and a half percent} for 30- -60 miles more from a full charge. Okay, Elon probably knows w/ a few of his aerodynamicist engineers what the reduction of the C/Ds (from hisNot only the heater uses your battery, but also other factors such as air pressure (drag down your car), electron flow resistant from anode to cathode. So, EV is not very friendly with cold weather
diameter) rear view side cameras will do feeding the viewing screens just behind the A pillars inside the door. That ogre' NHTSA's still out to lunch with that baby FMVSS!
