Scheduled Departure for AM Commute---uses more than saves?

[user212_nr]

It looks like the car used approximately 8% charge, or approximately 22 miles of range to precondition. My entire drive to work is 12 miles. Seems a little backwards to use 22 miles of range to prepare for a 12 mile trip?

You are not properly comparing the numbers. The "miles of range" are a very generous estimate. It is not uncommon to use 22 "miles of range" for a 12 mile trip when you consider climate and a frozen battery.

The car will heat the cabin when you start driving, so all you loose is the loss during the time that you spent warming it up. You could say that it is a waste to heat your car at all during a 12 mile drive. Why not just wear a jacket and hat... where you draw the line is up to you.

 

[Rottenapplr]

Never use preconditioning. Then again I'm in California and its not that cold. I do leave the ac on when its the summer and i need to run in. Love this about EV.

 

[gregtopf]

You are not properly comparing the numbers. The "miles of range" are a very generous estimate. It is not uncommon to use 22 "miles of range" for a 12 mile trip when you consider climate and a frozen battery.

But you did not note the second part of my "assumption" which is based on efficiency as well. Assuming a 50% reduction in efficiency based on the cold, my 12-mile drive would use 24 miles of range with no preconditioning. So preconditioning using 22 miles of range plus assuming I get 100% rated miles in the drive with a warm batter, 12 miles of driving uses 34 effective miles of range to get to work.

Yes, I am aware that miles of range is not equal to actual miles, but I'm using is as an apples to apples here.

In reality, I can run the HVAC for ten minutes to get the cabin up to temp for my comfort.

The query behind the initial thread is whether letting the battery warm for 60 minutes gives some other benefit in a short drive.

That all said, this is a really good thread with lots of great responses, so I really appreciate everything...keep it comin!

 

[user212_nr]

But you did not note the second part of my "assumption" which is based on efficiency as well.

...assuming I get 100% rated miles in the drive with a warm batter

You can't do precise math with such generous assumptions. Even if your battery is warmer, then you still have the cabin to heat (let alone the driving style and conditions), you will not be getting rated miles.

The query behind the initial thread is whether letting the battery warm for 60 minutes gives some other benefit in a short drive.

I only know the info on the Tesla website about "Scheduled Departure", it mentions nothing about a 60 minute period. If you or others have links... I'm not saying that it isn't true, just can't find that allegation.

The battery is warmed in order to charge, so scheduled departure in theory (as I read it) delays charging so that the battery will not cool off before driving. The battery is also warmed as a part of the normal pre-conditioning ("climate on"). Some users report that the battery is heated anytime they prepare to drive, so all SD does is eliminate the wasted cool-down after charging. If you are charging at low amperage (120v especially), you won't see the benefit of a warmer battery during charging.

If you leave at the scheduled time (or slightly earlier if they allow), it is almost impossible for it to use more energy. Other than for the fact that for your 10 minute drive the cabin will at 40 degrees for 2 minutes, you'll never get an accurate number.

 

[BeeGood]

For a new owner (i.e., me) this still sounds confusing. I think the bottom line takeaway is scheduled departure (which has an element of preconditioning) is best used for longer commutes. But for a short commute, just heat up the cabin via mobile app a few minutes before leaving and don't worry about maxing out the region recovery, etc.

Am I interpreting this correctly?

That is correct, but in all honesty, it’s not a huge deal.

Yes scheduled preconditioning costs you a few kWh, but we’re really talking about pennies versus turning on the climate controls from your phone.

I wish that Tesla would separate cabin heating and battery conditioning in the schedule menu.

 

[JCtx]

I wish that Tesla would separate cabin heating and battery conditioning in the schedule menu.

It should be separated everywhere, including the app. Don't understand why they haven't done that. Just add a separate 'button'.

 

[BeeGood]

It should be separated everywhere, including the app. Don't understand why they haven't done that. Just add a separate 'button'.

Agreed, I don’t understand why you can’t adjust the schedule from that app. Would be nice on the occasions when I’m laying in bed and realize I have to make a long drive in the AM to just quickly readjust it.

 

[Rocky_H]

Agreed, I don’t understand why you can’t adjust the schedule from that app. Would be nice on the occasions when I’m laying in bed and realize I have to make a long drive in the AM to just quickly readjust it.

But that's why I think this scheduled departure stuff is frustrating and mostly useless.
That thing you want to do, where you realize you have a long drive in the morning, I can do all that from my app from just having scheduled start time turned on at 1:00 AM. Just open the app, move the charge limit slider up to 90 or 95% or whatever, and it will run that night at 1:00 AM. Easy peasy. Or if it's already early morning and charging has finished, still move the limit up, and then hit the "Start Charge" button in the app.

 

[BeeGood]

But that's why I think this scheduled departure stuff is frustrating and mostly useless.
That thing you want to do, where you realize you have a long drive in the morning, I can do all that from my app from just having scheduled start time turned on at 1:00 AM. Just open the app, move the charge limit slider up to 90 or 95% or whatever, and it will run that night at 1:00 AM. Easy peasy. Or if it's already early morning and charging has finished, still move the limit up, and then hit the "Start Charge" button in the app.

I guess that will work sometimes but it has its limits.

What if you’re already charging to 90% SOC and you realize you have to leave the house 3 hours earlier? Pushing the slider up isn’t going to help you.

Or, more commonly for me, what if I realize that I don’t have to leave at all and want to turn off preconditioning/cabin heating for the day? You either go to the car and turn it off or let it run for no reason.

It seems like it would be pretty simple to just add the scheduler, precondition (yes/no), climate (yes now). A time scroll wheel and two toggles in the app.

 

[Rocky_H]

I guess that will work sometimes but it has its limits.

Everything does.

What if you’re already charging to 90% SOC and you realize you have to leave the house 3 hours earlier? Pushing the slider up isn’t going to help you.

I guess I'm not following you at all. Looked at one way, nothing in the world could help you in that case. If you suddenly discover you have to leave in 10 minutes, but the car needs 2 or 3 hours of charging, no software update or user interface method can solve that. Or looked at another way both scheduled start or scheduled end would both work fine if there is enough time between when you find out this change and when you have to leave. What are you getting at? As soon as you discover this 3 hour time shift, move the slider up and tell it to start charging. That is the fastest it can do. What more could you possibly want, or makes you think this doesn't work?

Or, more commonly for me, what if I realize that I don’t have to leave at all and want to turn off preconditioning/cabin heating for the day? You either go to the car and turn it off or let it run for no reason.

Well, I guess that's a separate issue. I think that's just a waste of energy, so I would never use it, so that solves that.

It seems like it would be pretty simple to just add the scheduler, precondition (yes/no), climate (yes now). A time scroll wheel and two toggles in the app.

I do certainly agree that they need to separate the charge scheduling from the pre-warming the cabin.

 

[BeeGood]

Everything does.

I guess I'm not following you at all. Looked at one way, nothing in the world could help you in that case. If you suddenly discover you have to leave in 10 minutes, but the car needs 2 or 3 hours of charging, no software update or user interface method can solve that. Or looked at another way both scheduled start or scheduled end would both work fine if there is enough time between when you find out this change and when you have to leave. What are you getting at? As soon as you discover this 3 hour time shift, move the slider up and tell it to start charging. That is the fastest it can do. What more could you possibly want, or makes you think this doesn't work?

Well, I guess that's a separate issue. I think that's just a waste of energy, so I would never use it, so that solves that.

I do certainly agree that they need to separate the charge scheduling from the pre-warming the cabin.

I think we might have our wires are crossed here.

The first post of mine you replied to was:

Agreed, I don’t understand why you can’t adjust the schedule from that app. Would be nice on the occasions when I’m laying in bed and realize I have to make a long drive in the AM to just quickly readjust it.​

But before that, I posted:

I wish that Tesla would separate cabin heating and battery conditioning in the schedule menu.​

I’m not sure how you interpreted that, but what I’m saying in these posts is that I would like Tesla to separate battery precondition and cabin heating and allow us to schedule both from the app.

Your reply (if I’m understanding you correctly) is to adjust the SOC slider. If you’re saying that because it will start the battery warming earlier, I agree. However, it doesn’t give you the functionality I described above.

 

[Rocky_H]

Oh, right. I'm still just thinking of charge scheduling. I keep forgetting people would use that pre-warming.

 

[BeeGood]

Oh, right. I'm still just thinking of charge scheduling. I keep forgetting people would use that pre-warming.

Yeah, and to be honest, I wouldn’t use it that much. Like you said, it’s a waste of energy in most situations, but it is nice to have full regen braking from the start since I’ve come to really like one pedal driving. So the choice would be nice.

The main thing I would want is to be able to schedule cabin heating from the app without the battery preconditioning.