Precondition car plugged in vs not plugged in

[MikeHolliday]

Or the Value you place on One Peddle Driving... I love one peddle driving...

 

[Gasaraki]

I'm interested in maximising range. There's a rare round trip I will need to make which will be border line do-able without a charging stop. The quoted range for the 2021 UK model 3 is 360 miles. On a recent shorter trip in 40 degree F temps I calculated it out to be not much more than 200 miles which I found disappointing. I know the range will be better in the summer (it rarely gets into the 80s in the UK) but I'm wondering how much higher that 200 range would have been had I preconditioned via the wall before the trip.

I agree no point preconditioning for any other reason than maximizing range.

Not anywhere close to 360 miles. Even in the summer time, to get 360 miles you'll probably have to drive 55 miles per hour the whole way and have no headwind and aero wheels and no passengers, etc, etc.

 

[JCtx]

Not to mention charging to 100%, and arriving with negative range... if you arrive at all. I've NEVER heard of an M3 running more than its 'wonderland' rated figure of 353 .

 

[MikeHolliday]

Not anywhere close to 360 miles. Even in the summer time, to get 360 miles you'll probably have to drive 55 miles per hour the whole way and have no headwind and aero wheels and no passengers, etc, etc.

When (In the US) the EPA does range tests they test every car under the same conditions. It is also a combination of City/Highway. In November in my Model Y (326 mile range) with an outside temperature of 37 degrees Fahrenheit, Climate Control set to 71 degrees Fahrenheit with an average speed of approx. 72 mph on a 600 mile trip I was able to go 200 miles from Lexington, Ky 90% (Dsoc) to Worthington, Oh 19% (Asoc). That is a expected range of 280 miles. That is an 88% efficiency at that speed and temperature.

Remember that the new Model 3 and the Model Ys are using the Octavalve Heat Pump. I find that if the car is pre-conditioned prior to departure the heat pump makes no more difference than the air conditioner.

I would like to see someone put an Amp meter on the heat pump and measure the current draw at different winter outside ambient air temperatures for heat and then in the summer for different outside ambient air temperatures for cooling...

 

[Two-rocks]

Read the beginning, but not all of this thread. The OP and few posts that follows may not applicable to the heat pump vehicles. Specifically, it was stated that the vehicle needs up to 14kw for pre heating.

my ChargePoint app tells me the draw just to run the heat pump is about 800 watts (cabin heating only). I’ve see up to 6kw, with defrost and battery icons present. Much colder weather on the way, so further testing is needed.

that said the heat pump was a significant factor is the decision buying process, as we live where it’s cold and experienced the resistive heating range loss in a BEV (our eGolf)

 

[MikeHolliday]

The reason that I believe that pre-heating is extremely important is because of this simple factor.

I have owned many traditional and performance ICE cars and I currently own two (50 plus year old British cars) restored plus my wife's car.

What I have really notice in cold weather (between 17 and degree 35 degrees Fahrenheit) is how much warmer my feet are on the floor. In a traditional ICE car you have a thin piece of sheet metal with insulation and carpet on top and the cold tends to easy transfer due to the coupling effect of the metal. With the Tesla's battery being under your feet the warm battery radiates heat vs transferring the cold. I can keep the climate control in my Model Y set much lower than any of the ICE cars that I have owned and still keep my feet warmer, therefore saving energy and increasing the range by pre-conditioning the car prior to driving.

 

[tinkererguy]

Really thorough new video about cold weather charging at various amp settings by Bjørn Nyland here, using OBD readings to directly see the things the Model 3 does trying to keep the pack warm, even when there's as few as 13 amps of power available:

figured folks reading this thread might find it interesting.

 

[CarlZ]

Please help a Tesla noob here.. 2021 SR+ and I live in a condo with no charger or internet (car parked in basement level 4. Good news I’m yet to see the and I live in Toronto even when it’s -1 C outside the car park seems to be around 10-11C. Question do I need to precondition before I take the car out? I can’t remotely control it via the app and have to take the elevator down 20 stories to turn the cabin heat on? Can I just turn the heat on for 5mins before I drive? Is there an ideal time? My friend don’t worry abt preconditioning since driving the car heats up the battery too and the only perk is I’ll have regen and Tesla battery management system is pretty good compared to most other EVs..

 

[MikeHolliday]

It depends on your charge state and the distance driving. Preconditioning the battery regardless of the temperature will ensure that you you burn the lowest Wh/mile and have a longer range. The Snowflake means the battery is really cold, like brrrr... Preconditioning also helps the life of the battery and if the battery is cold you will get very little regen braking. Schedule the departure time and the car will figure out when to start the preconditioning. Do you not even have a 120 volt outlet in the garage that you can use. At 120 volts you can old draw 1,800 watts through a standard 120 volt outlet (20A) which is 1.8 Kilowatts. Where I live I pay about $0.12/Kwh equals about $0.216/hour of charging. There is now a Charge history in the car which will tell you each night how much power is used. In the US garages must have 120 volt outlets just to meet code even before EV's. You do not have to go to the garage, you can Schedule a departure time to have the car preconditioned.

 

[CarlZ]

It depends on your charge state and the distance driving. Preconditioning the battery regardless of the temperature will ensure that you you burn the lowest Wh/mile and have a longer range. The Snowflake means the battery is really cold, like brrrr... Preconditioning also helps the life of the battery and if the battery is cold you will get very little regen braking. Schedule the departure time and the car will figure out when to start the preconditioning. Do you not even have a 120 volt outlet in the garage that you can use. At 120 volts you can old draw 1,800 watts through a standard 120 volt outlet (20A) which is 1.8 Kilowatts. Where I live I pay about $0.12/Kwh equals about $0.216/hour of charging. There is now a Charge history in the car which will tell you each night how much power is used. In the US garages must have 120 volt outlets just to meet code even before EV's. You do not have to go to the garage, you can Schedule a departure time to have the car preconditioned.

Thank you.. unfortunately it will cost me around 4-5k to get an outlet installed (level 2) and there’s isn’t a 110v outlet (designated parking spots) I’m trying to figure out if it’s worth the money and hassle (need to get permits + condo board approval + lawyer fees) too many red tapes in Toronto. I also don’t drive much and keep the battery at 55-65% at all time and works from home remotely (will continue post pandemic) don’t want to ruin the battery by not preconditioning it but is it true that it let me use certain portion of the battery while it’s cold and once I start driving and as the battery heats up it gives me back my regen plus the other portion of the battery ?

 

[Les236]

I live outside of Boston, so not as cold as you, but I rarely precondition my MX because I rarely know when I am leaving. So I just go. When it is below freezing I can go 20-30 miles or more before the battery is fully warmed. Once you start driving the heat from the motors and possibly the cooling system will start to warm the batteries. My drives are mostly around town so rarely do I get out onto the highway right away, but I have on long trips when waking up at a hotel. So yes, once you drive for a while as the battery warms, you start getting more and more regen until eventually you'll have full regen.

 

[CarlThompson]

From what I've read, charging a lithium ion battery quickly while it's cold can damage the battery and that's why Tesla limits regen when cold to a slower safe level. (And why a Tesla heats the battery first when plugged in at cold temps before starting to charge quickly.) But discharging a lithium ion battery when cold does not cause damage. So driving in the cold without preconditioning should be just fine if you don't mind the loss of regen.

 

[drtimhill]

Thank you.. unfortunately it will cost me around 4-5k to get an outlet installed (level 2) and there’s isn’t a 110v outlet (designated parking spots)

One thing several of my friends in condos have done is negotiate switching parking spots so you are close to a 120V outlet ..though you might run foul of the resident association for who foots the power bills.

 

[Brock-WI]

Carl, it doesn't hurt the car at all to not be pre-conditioned, the car won't let you do things to the battery to damage it, it will just reduce power if it is really cold and have little to no regen. Last winter our car would sit outside for 12+ hours at -15F or -25C and the car works fine, but no regen at all at those temps and it does limit the acceleration power as well. I have "scan my Tesla" so I can see once I start driving it when it's that cold it does actively heat the battery, but again the car will do what it does, just don't expect regen or sub 5 sec 0-60

The biggest advantage I see for pre-heating is if you have a longer trip that is pushing the full range of the car because it will use additional power warming up the battery (and cabin) while you are driving, thus bringing your range down significantly, I have seen it as low as half my summer range in these conditions even with no snow covered roads. Basically if you can pre-heat with 6kwh from the grid to get the battery up to temp, that is 6kwh it doesn't have to pull from the battery once you are moving.

If I recall correctly if the pack get below 0F it does wake up and heat the pack

The second biggest advance is the comfort for those driving and or riding

 

[57nevets]

As others have mentioned, preheating is primarily aimed at occupant comfort. If you have a longer trip and preheat you are basically using power from the wall and not from the battery. If you look at a 30 mile trip in winter that might consume 10 kWh of battery if the car is cold. Now if you preheat that same car it might consume 11kWh total but 3 kWh came from the wall. So at the end of your trip the cars battery will have consumed only 8 kWh instead of 10 kWh.

Strictly from an energy standpoint preheating consumes more energy but leaves more energy in your battery. I believe this would also cycle the battery LESS than if you didn't preheat. In the grand scheme of things I think this is less than anything measureable on the batteries life. Again going back to occupant comfort.

The time it is beneficial (beside comfort) is if your going on a long trip, essentially adding 3kWh to you pack size, only becasue you consume it from the wall rather than from the battery once your moving down the road.

 

[57nevets]

With winter here I keep my 2021 SR+ plugged into a 14/50 outlet and the charge level set to 90%. Mostly short trips so precondition enough to warm the car or defrost the glass. After reading this thread I thought I should rethink the 90% charge level but on its Charging Habits web site, Tesla suggests 90%:

• (For RWD vehicles) If the image of the Battery displays ‘Daily’ and ‘Trip’: keep the full charge limit of the battery to under 90% for daily use by using the mobile app or vehicle’s touchscreen to set charge limit within the ‘Daily’ range. If you need the full range (i.e. 100%) of your battery for a long-distance trip, you can increase the limit to the ‘Trip’ range (>90%) as necessary.
• For All-Wheel Drive vehicles, keep the full charge limit of the battery to under 90% for daily use by using the mobile app or vehicle’s touchscreen to set charge limit within the ‘Daily’ range. If you need the full range (i.e. 100%) of your battery for a long-distance trip, you can increase the limit to the ‘Trip’ range (>90%) as necessary.

Range Tips | Tesla Support UAE

Your Tesla vehicle continuously monitors its energy level and proximity to known charging locations to provide range assurance. To maximize efficiency, it is important to know the factors that impact range and the recommended ways to reduce energy consumption.

www.tesla.com

 

[EVJAutoJunkie]

I set my charge limit to 80% @ 48A with a ChargePoint Home Flex (FYI - Much better charger than Tesla's wall charger for cold outdoor climate, IMO). I anticipate faster battery drain with a car parked in sometimes single digit temperatures.

It is difficult to precondition the car when you don't have a regular daily driving schedule. However, I find that if I set it to precondition within a 30 min window of deciding to ride out, it does get it ready on time, especially at that higher charge rate. However, I have preconditioned the car at times while unplugged when I have multiple drives in a day. But I do notice it burns off an extra 1% - 2% vs the car plugged in. That's obviously because when the car is plugged in, the battery charger detects the % loss from the preset SOC limit and quickly tops it off. That is why I keep the car plugged in every night, even if I only burned 2% battery on a short drive earlier in the day.

 

[tm1v2]

Please help a Tesla noob here.. 2021 SR+ and I live in a condo with no charger or internet (car parked in basement level 4. Good news I’m yet to see the and I live in Toronto even when it’s -1 C outside the car park seems to be around 10-11C. Question do I need to precondition before I take the car out? I can’t remotely control it via the app and have to take the elevator down 20 stories to turn the cabin heat on? Can I just turn the heat on for 5mins before I drive? Is there an ideal time? My friend don’t worry abt preconditioning since driving the car heats up the battery too and the only perk is I’ll have regen and Tesla battery management system is pretty good compared to most other EVs..

I would bet money that preconditioning before driving always uses more electricity than just letting the car warm up as it drives.

The reasons to precondition are:

• If you can precondition while plugged in, then you can minimize battery use while driving. The extra electricity to precondition can come from the wall instead.
• If you like the experience of starting your drive with a warmed up car - more power and regen available, and a warm cabin.

Having greater regen available from the start of a drive could help compensate for some of the preconditioning energy use, but I don't think it would ever compensate for all of it even in stop-n-go rush hour traffic.

 

[rpiotro]

When (In the US) the EPA does range tests they test every car under the same conditions. It is also a combination of City/Highway. In November in my Model Y (326 mile range) with an outside temperature of 37 degrees Fahrenheit, Climate Control set to 71 degrees Fahrenheit with an average speed of approx. 72 mph on a 600 mile trip I was able to go 200 miles from Lexington, Ky 90% (Dsoc) to Worthington, Oh 19% (Asoc). That is a expected range of 280 miles. That is an 88% efficiency at that speed and temperature.

Remember that the new Model 3 and the Model Ys are using the Octavalve Heat Pump. I find that if the car is pre-conditioned prior to departure the heat pump makes no more difference than the air conditioner.

I would like to see someone put an Amp meter on the heat pump and measure the current draw at different winter outside ambient air temperatures for heat and then in the summer for different outside ambient air temperatures for cooling...

You can put an ammeter on it. If you are plugged in but not charging you can see what the car is drawing on the display.

I was in my car the other day. Ambient temp was 32°F. I turned on the front and rear defrosters which sets the HVAC on high. Also the drivers seat was on high and the steering wheel was being heated. It peaked out at 24 amps x 240V = 5760 watts. Pretty significant draw. I then turned everything off except auto HVAC with the interior temp set to 68°F. It bounced between 2 and 8 amps. Must be due to cycling of the compressor.

You can see that preheating, conditioning and/or deicing can draw a significant amount of juice. Better to do that hooked up if you can rather than drawing down the battery. Especially if you are departing on a long trip and need the range.

 

[CarlZ]

Carl, it doesn't hurt the car at all to not be pre-conditioned, the car won't let you do things to the battery to damage it, it will just reduce power if it is really cold and have little to no regen. Last winter our car would sit outside for 12+ hours at -15F or -25C and the car works fine, but no regen at all at those temps and it does limit the acceleration power as well. I have "scan my Tesla" so I can see once I start driving it when it's that cold it does actively heat the battery, but again the car will do what it does, just don't expect regen or sub 5 sec 0-60

The biggest advantage I see for pre-heating is if you have a longer trip that is pushing the full range of the car because it will use additional power warming up the battery (and cabin) while you are driving, thus bringing your range down significantly, I have seen it as low as half my summer range in these conditions even with no snow covered roads. Basically if you can pre-heat with 6kwh from the grid to get the battery up to temp, that is 6kwh it doesn't have to pull from the battery once you are moving.

If I recall correctly if the pack get below 0F it does wake up and heat the pack

The second biggest advance is the comfort for those driving and or riding

Thank you this is helpful.. I’m going to stop stressing about preconditioning I always plug in when I’m out and 8/10 times I’m able to find a level 2 charger in the city (groceries, malls etc) I do SC maybe once a month.