Scheduled preconditioning really helps

[pshifrin]

I drive my son to school early in the morning. Until this week, he was hybrid, 2 days per week in-person so a few minutes before, if I could remember, I’d preheat from the app. Now that he’s back 5 days a week, I set the scheduled departure in the car for 7:15am. With similar temperature conditions and highway speeds, I was using about 10% of the battery round trip and with the schedule departure method only 5%!

p.s. the car is plugged in overnight but outside, I have an outdoor 240 charger but no garage

 

[Rocky_H]

With similar temperature conditions and highway speeds, I was using about 10% of the battery round trip and with the schedule departure method only 5%!

The title of your thread says "Preconditioning really helps!" but you realize this isn't saving any energy, right? You seem really excited about this as if you think this is using less energy, but it isn't. All of the energy is still being used, but it's just using more of it directly from the wall at your house FIRST before you leave, and is actually probably using more than it needs to that way, so this actually wastes some extra energy.

 

[jcanoe]

A benefit of preconditioning the Tesla in colder temperatures is that the battery pack will be warmed. The impact of the colder temperature on regenerative braking is minimized. If you mostly charge at work or at a free to use public charging station you are not directly paying for the energy used to precondition the Tesla or for driving.

 

[pshifrin]

The title of your thread says "Preconditioning really helps!" but you realize this isn't saving any energy, right? You seem really excited about this as if you think this is using less energy, but it isn't. All of the energy is still being used, but it's just using more of it directly from the wall at your house FIRST before you leave, and is actually probably using more than it needs to that way, so this actually wastes some extra energy.

You are correct, I didn't account for that, my analysis was simply from the car driving efficiency standpoint. However, I'm fortunate to not be paying directly for almost all of my charging right now.

 

[pt19713]

The title of your thread says "Preconditioning really helps!" but you realize this isn't saving any energy, right? You seem really excited about this as if you think this is using less energy, but it isn't. All of the energy is still being used, but it's just using more of it directly from the wall at your house FIRST before you leave, and is actually probably using more than it needs to that way, so this actually wastes some extra energy.

Yes and no. If you time both the charging of the battery and heating up the cabin, you can yield about 10% net efficiency assuming the drive is longer than a10 miles one way. You're correct in that the energy used and the breakeven point needed to get back that energy can be high. If the car is sat idle and you precondition from the app and not charging, 15 minutes will take about 2 kWh of energy. For me, I need to drive 40 miles to get that back (comparing the efficiency of a battery pack that's 40 deg F versus one that is 65 deg F). But, if you time the charging within 1-2 hours before leaving, there really isn't much wasted energy.

For longer trips, the preconditioning is going to pay off. Bjorn tested 20% higher efficiency with a preconditioned battery on a Model 3. My tests show 15% on a Model Y.

 

[CapsEngineer]

Does just activating the climate provide preconditioning?

 

[jcanoe]

Does just activating the climate provide preconditioning?

If you mean turning on the climate control via the Tesla app, then yes that will precondition the passenger cabin and may warm the battery pack depending on the temperature of the pack.

 

[jcanoe]

If the battery pack is being warmed during preconditioning a small red battery icon appears on the climate control screen within the Tesla app.

 

[ChrisMPK]

I think you're missing the point. By preconditioning, you will start and end your trip with a higher SOC. Also, the car will be easier to drive (regen at full) and more comfortable (cabin preheated). Also, if you are on a TOU plan, you are more likely to be using low cost energy assuming you have entered the appropriate info into the scheduled departure settings.

 

[jcanoe]

I preconditioned the hell out of my Model Y this winter and never got full regen back. Usually at least 5 dots remained after preconditioning. Still quite usable and much better than the alternative, i.e. not preconditioning and having no discernible regen at all.

 

[pt19713]

I preconditioned the hell out of my Model Y this winter and never got full regen back. Usually at least 5 dots remained after preconditioning. Still quite usable and much better than the alternative, i.e. not preconditioning and having no discernible regen at all.

2021.4.11 fixed most of that! I guess we'll see the benefit in 8 months.

 

[juicevibes]

I think you're missing the point. By preconditioning, you will start and end your trip with a higher SOC. Also, the car will be easier to drive (regen at full) and more comfortable (cabin preheated). Also, if you are on a TOU plan, you are more likely to be using low cost energy assuming you have entered the appropriate info into the scheduled departure settings.

Sorry what is SOC and TOU? I'm a newbie here and trying to learn more about this car. Thanks!

 

[CapsEngineer]

Sorry what is SOC and TOU? I'm a newbie here and trying to learn more about this car. Thanks!

SOC = State of Charge
TOU = Time of Use -- Some electric companies will vary your charges based on the time of day. So electricity used in the middle of the night is cheaper than that used in the middle of the day.

 

[jcanoe]

Sorry what is SOC and TOU? I'm a newbie here and trying to learn more about this car. Thanks!

In Southern California there are multiple TOU electric utility rate plans. Look up TOU 5, I believe that plan offers some of the lowest rates for the hours between 1200 and 0600.

 

[juicevibes]

SOC = State of Charge
TOU = Time of Use -- Some electric companies will vary your charges based on the time of day. So electricity used in the middle of the night is cheaper than that used in the middle of the day.

Awesome! Thanks for the info.

 

[juicevibes]

In Southern California there are multiple TOU electric utility rate plans. Look up TOU 5, I believe that plan offers some of the lowest rates for the hours between 1200 and 0600.

Thanks. I'll look this one up for sure.

 

[ACofNY]

In my case where I only have 110v 20 amp charging at home, it does not work out. It uses and drains the battery to precondition the car. With delayed charging, when I get in the car at 7 am, it says it will complete charging at 10 AM. I find when it is cold out, I drive home and charge right away since the battery is warm. Also, since my M3 does not have a heat pump, i rather take off without heat on and let the driving heat everything up. After a while, then I turn the cabin heat. i find that is the most efficient way, but I do lose regen for some time. Why am I doing this? My daily trip is very short, and I lose over 50 percent efficiency in the winter If I drive as I would normally with heat. And it takes quite a bit of time to charge especially if I try the precondition/delay charging. Tesla algorithm does not account for 110v charging.

 

[jcanoe]

In my case where I only have 110v 20 amp charging at home, it does not work out. It uses and drains the battery to precondition the car. With delayed charging, when I get in the car at 7 am, it says it will complete charging at 10 AM. I find when it is cold out, I drive home and charge right away since the battery is warm. Also, since my M3 does not have a heat pump, i rather take off without heat on and let the driving heat everything up. After a while, then I turn the cabin heat. i find that is the most efficient way, but I do lose regen for some time. Why am I doing this? My daily trip is very short, and I lose over 50 percent efficiency in the winter If I drive as I would normally with heat. And it takes quite a bit of time to charge especially if I try the precondition/delay charging. Tesla algorithm does not account for 110v charging.

If there is only the one 20A receptacle on the circuit an electrician may be able to rewire this for 240V using the existing wiring. There would need to be space in your home's electrical service panel for a 20A double pole circuit breaker. The power would be doubled, you charging time halved.

 

[flyhighboi20]

I think you're missing the point. By preconditioning, you will start and end your trip with a higher SOC. Also, the car will be easier to drive (regen at full) and more comfortable (cabin preheated). Also, if you are on a TOU plan, you are more likely to be using low cost energy assuming you have entered the appropriate info into the scheduled departure settings.

My utility company sucks for TOU, on my plan from Oct-May its 1 whole cent difference per KWH lol. I called them and asked if this plan was a joke, they told me between Jun and Sept its 5 cents difference. So I don't worry about when I plug in anymore. I have seen other people utility bills that it makes a huge difference, just 30 miles south of me with a different utility company the difference was massive.

 

[Jromf]

Sorry what is SOC and TOU? I'm a newbie here and trying to learn more about this car. Thanks!

Get used to the abbreviations. I joined 10 months ago and they make me tired. Here’s a short list. Tesla terms and abbreviations