How much energy does pre-conditioning take?

[dpilot83]

If it's 10 degrees F outside and I pre-condition the vehicle while it's plugged in, how much energy will that take?

I'm assuming maybe 40 amps for 20 min or 3.2 kWh?

I'm looking at buying a Model Y LR and I'm comparing it to energy costs for an ICE vehicle. Trying to nail down all costs. Thanks.

 

[plastrd]

I haven't had the car long enough yet to have been through a 10F morning but I do have some data from a 32F morning this week that might be relevant.

Scheduled departure is set for 7:30 with preconditioning enabled on weekdays.
I have a 240V 20A outlet for my charger so it is being fed ~4kW overnight and reached 80% charge limit at 6:35AM and stopped charging.
Then at 6:45 it resumed charging probably to prepare for preconditioning, maybe because I only have 4kW available and it anticipates using more and draining the battery below the charge limit.
Preconditioning and climate control kicked on at 7:10, preconditioning stopped at 7:15 when I unplugged the charger and left for work.
I left before the 7:30 scheduled departure but the cabin felt warm enough already with only 5 minutes of preconditioning. The graph didn't fit in my screenshot but the cabin temperature went from 35F to 65F in that 5 minutes from 7:10 to when I left at 7:15.
However, I did have reduced regen for the first few miles of the trip since the battery was probably still cold. Maybe if I hadn't left early the preconditioning would have heated the battery more to allow better regen but I didn't mind exercising the brake pads.

View attachment 986034

 

[plastrd]

My screenshot disappeared and apparently I can't edit my post to add it back, trying again:

 

[tashtibet]

switched to EVs since 2016-owning an ICE is a pure rip off. Don't let futile things stop you from moving ahead.

 

[Jerry Ham]

switched to EVs since 2016-owning an ICE is a pure rip off. Don't let futile things stop you from moving ahead.

Completely agreed. Doing a calculation of gas used when warming up a car, adding in the costs to run block heaters, and then calculating that against preconditioning an EV is a useless exercise. Nothing takes anywhere near the energy of actually moving the car as you'll quickly see when driving it. EV driving is so much superior - you can't just do a cost calculation as there are so many other benefits. Even something as simple as not having to smell gas fumes in your garage and at a gas station ends up being just wonderful. I'm a little behind you (went to a Model S in 2017 and my wife to a Model 3 in 2018) but still have 6 years of ICE free driving and would not go back...

 

[jcanoe]

A couple of point re preconditioning:

When you precondition the Tesla Model Y when the battery is cold, i.e. below 4C (39F) the amount of battery warming that will be performed is not enough to enable full regenerative braking once you start to drive. Tesla has provided a setting under Pedals & Steering that will automatically blend the friction brakes with regenerative braking when regenerative braking is reduced or unavailable. Enable this setting and you will never experience a reduction in braking force when you lift your foot from the accelerator pedal when regenerative braking is reduced or unavailable.

As battery warming while preconditioning before driving is now limited the preconditioning function is primarily used to warm the passenger cabin. Unless the outside air temperature is well below 0C (32 F) you will only need to precondition for 10 minutes or less to bring the passenger cabin to your desired temperature. Set the heated (front) seats and steering wheel heater to Auto and the Tesla Model Y will automatically warm these during preconditioning.

If plugged in while preconditioning this will reduce the amount of energy that is drawn from the battery for the heat pump to operate, etc. while preconditioning. Battery warming will use stator heating and draws up to 3.5kW per drive unit stator (front and rear.) If you normally charge at 48A or 40A then most if not all of the power needed for preconditioning will come from the grid. If you normally charge at one of the lower amperage rates for Level 2 (240V charging) then some of the power used for preconditioning will be drawn from the high voltage battery. Preconditioning while plugged in using Level 1 charging (120V) will only provide a small percentage of the power used to precondition the Tesla Model Y.

In my experience preconditioning in the A.M. uses ~2% of the battery (In winter I generally precondition via the Tesla app before driving for ~8 minutes.) The Tesla app will notify you when the desired cabin temperature has been reached. I estimate it costs $0.10 to $0.15 to precondition my Model Y in the A.M. (in winter the temperature inside my unheated garage rarely falls below 0C (32F) but frequently does hover around that temperature early in the A.M. in the months of December, January and February.)

Special Use Case: when there is snow and ice on the Telsa vehicle, use the Defrost Vehicle function within the Tesla app as this setting will quickly begin warming the passenger cabin while also defrosting all of the windows, cameras, side mirrors, and charge port. Also, the rear hatch glass defroster will be turned on and the windshield wiper resting area of the windshield will be heated. (If there has been a decent snowfall you should brush any snow off the the Tesla vehicle (especially the roof, hood, lights and turn signals before starting to drive. Note that the LED lights don't generate enough heat to melt snow and ice from the headlights, tail lights, etc.

 

[dpilot83]

A couple of point re preconditioning:

When you precondition the Tesla Model Y when the battery is cold, i.e. below 4C (39F) the amount of battery warming that will be performed is not enough to enable full regenerative braking once you start to drive. Tesla has provided a setting under Pedals & Steering that will automatically blend the friction brakes with regenerative braking when regenerative braking is reduced or unavailable. Enable this setting and you will never experience a reduction in braking force when you lift your foot from the accelerator pedal when regenerative braking is reduced or unavailable.

As battery warming while preconditioning before driving is now limited the preconditioning function is primarily used to warm the passenger cabin. Unless the outside air temperature is well below 0C (32 F) you will only need to precondition for 10 minutes or less to bring the passenger cabin to your desired temperature. Set the heated (front) seats and steering wheel heater to Auto and the Tesla Model Y will automatically warm these during preconditioning.

If plugged in while preconditioning this will reduce the amount of energy that is drawn from the battery for the heat pump to operate, etc. while preconditioning. Battery warming will use stator heating and draws up to 3.5kW per drive unit stator (front and rear.) If you normally charge at 48A or 40A then most if not all of the power needed for preconditioning will come from the grid. If you normally charge at one of the lower amperage rates for Level 2 (240V charging) then some of the power used for preconditioning will be drawn from the high voltage battery. Preconditioning while plugged in using Level 1 charging (120V) will only provide a small percentage of the power used to precondition the Tesla Model Y.

In my experience preconditioning in the A.M. uses ~2% of the battery (In winter I generally precondition via the Tesla app before driving for ~8 minutes.) The Tesla app will notify you when the desired cabin temperature has been reached. I estimate it costs $0.10 to $0.15 to precondition my Model Y in the A.M. (in winter the temperature inside my unheated garage rarely falls below 0C (32F) but frequently does hover around that temperature early in the A.M. in the months of December, January and February.)

Special Use Case: when there is snow and ice on the Telsa vehicle, use the Defrost Vehicle function within the Tesla app as this setting will quickly begin warming the passenger cabin while also defrosting all of the windows, cameras, side mirrors, and charge port. Also, the rear hatch glass defroster will be turned on and the windshield wiper resting area of the windshield will be heated. (If there has been a decent snowfall you should brush any snow off the the Tesla vehicle (especially the roof, hood, lights and turn signals before starting to drive. Note that the LED lights don't generate enough heat to melt snow and ice from the headlights, tail lights, etc.

That is a fascinating reply. Thanks.

I'm looking at the month of January temp records (in Fahrenheit) for 2022 in my area:

- There were 2 days at or below 0 at 7 AM
- There was 1 day between 0 and 5 at 7 AM
- There were 4 days between 5 and 10 at 7 AM
- There were 2 days between 10 and 15 at 7 AM
- There were 6 days between 15 and 20 at 7 AM
- There were 6 days between 20 and 25 at 7 AM
- There were 6 days between 25 and 30 at 7 AM

The rest of the days were between 30 and 40 degrees F at 7 AM

Given that info, I wonder if it's going to take quite a bit more time to pre-condition both the interior and the battery in weather like that?

I also wonder how much trouble I'm going to have with the charge cable having ice on it some mornings? We can get a pretty good layer of frost as well as some snow sometimes. If I buy it soon it'll be without a garage for a year. Our new house should be built by then so the second year this should not be an issue.

 

[jcanoe]

Battery warming only happens as required, i.e. if the battery is too cold to charge. Once the battery temperature reaches ~4C/39F the battery is warm enough to charge. Tesla does not warm the battery as long or as much as in earlier releases of the Tesla software; continued warming of the battery takes longer and uses more energy. Instead, the Tesla vehicle can be driven when the blue snowflake is displayed (indicating that the battery is cold.) The reduction in power when the blue snowflake is displayed is not noticeable in normal driving. Turn on the blended friction braking option under Pedals & Steering and the Tesla Model Y will slow when you lift your foot as expected regardless of the amount of regenerative braking that is available due to lower battery temperature, high state of charge of the battery or other scenarios that might limit regenerative braking. I used to precondition my Model Y for extended periods of time yet regenerative braking would still be noticeably reduced after preconditioning. Now I precondition for ~8 minutes and just drive, don't notice any reduction in how quickly my Model Y slows when I lift my foot from the accelerator pedal. The blended friction braking works seamlessly.

When battery warming is taking place the Tesla Model Y will display a red heating grid symbol with 3 heating elements to indicate that the battery is being warmed (The Tesla Model 3, Model Y now use stator heating to warm the coolant in the drive unit motor before sending the warm coolant through the battery.)

After 90 minutes charging (Level 2, 30 amps) I have observed the heating grid icon indicating stator heating is being performed. This happens after charging has been completed, while preconditioning before driving and lasts for ~15 minutes. Some battery warming will take place but not nearly as much battery warming as before with earlier releases of the Tesla software. In my experience the blue snowflake icon may remain even after the battery warming has completed. Battery warming does take place when preconditioning for Supercharging. To precondition for Supercharging you must select the Supercharger as the destination in the Tesla navigation system and be actively driving (The Tesla Model Y won't precondition for Supercharging while parked.)

It is possible to enter a nearby Supercharger location as the destination in the navigation system and then drive for ~20 minutes. This will significantly warm the battery while also consuming ~7kW while stator heating is active. You might get close to full regenerative braking after doing so but this would consume a couple of kWh and you could have had the same perceived level of regenerative braking by just turning on blended friction braking.

 

[Beans4Me]

Just started seeing 30s this weekend and I noticed it was pulling 2-4kwh from the wall connector while preconditioning. It preconditioned pretty quick, 10mins maybe but we probably let it go for 30mins. Once the cabin reaches temp it drops down to about 1kwh on the wall connector. So nice to hop into a toasty warm car. It’s my first car with a heated steering wheel. So nice.