Departure Time - I think I understand now

[flixden]

I have been doing tests forth and back with the scheduled departure time, and I think I finally figured it out.
This response from another thread has helped me come to my conclusion: Tesla scheduled departure/off-peak charging not working

In summary:
The scheduled departure time really means nothing with regards to when the charging starts. What's important is the Off-Peak End Time. The car will charge such that it has completed charging to the set charging limit by the Off-Peak End Time.

In both examples below I set the charge limit to only 5% above the current SOC, such that the required charging time is only ~ 30 minutes, for testing purposes:
- When I set the departure time to tomorrow morning, and select Preconditioning, the charging will start immediately and it charges to the set charge limit. The departure time is only used for the preconditioning in that case.
- when I then set the departure time to 10pm, de-selected preconditioning, and set the Off-Peak End Time to 9pm, the charging was delayed until about 8:15 and started at that time (just in time to finish at 9pm)
- I am now doing a third test: I set the departure time to 8:00am (tomorrow morning), and the Off-Peak End Time to 10pm. I bet that charging will start at around 9:15, and end just before 10pm tonight.

This is very confusing, and not really as explained in the manual. Or at least it's not the way I understood it from the manual. But I think I got it now.
It somewhat explains why you can't set a departure time without selecting OFF-Peak or Precondition.
Are you guys seeing the same behavior?

 

[gtae07]

That's been my experience in three weeks of owning the car... "Scheduled charging" = "Start charging at this time" and "Off peak" = "finish charging at this time".

My general use case is to set the off-peak time and departure/precondition to the same time (0445 off peak every day, 0445 departure weekdays) and both usually finish about 15 minutes ahead of time. My actual "super off peak" time ends at 0700 so if I weren't leaving till after that, I'd use that as the end time.

I agree that the UI for this is poor and should have better explanations, and more options than just "weekdays" or "all week". But for the latter I'm not sure whether a third-party app purchase/subscription is worth it just to manage different schedules vs. just doing it myself manually, especially since there will be days that will result in manual overrides anyway.

It would also be nice if the "precondition" setting let you input the desired HVAC settings rather than just using "last used".

 

[flixden]

I have been doing tests forth and back with the scheduled departure time, and I think I finally figured it out.
This response from another thread has helped me come to my conclusion: Tesla scheduled departure/off-peak charging not working

In summary:
The scheduled departure time really means nothing with regards to when the charging starts. What's important is the Off-Peak End Time. The car will charge such that it has completed charging to the set charging limit by the Off-Peak End Time.

In both examples below I set the charge limit to only 5% above the current SOC, such that the required charging time is only ~ 30 minutes, for testing purposes:
- When I set the departure time to tomorrow morning, and select Preconditioning, the charging will start immediately and it charges to the set charge limit. The departure time is only used for the preconditioning in that case.
- when I then set the departure time to 10pm, de-selected preconditioning, and set the Off-Peak End Time to 9pm, the charging was delayed until about 8:15 and started at that time (just in time to finish at 9pm)
- I am now doing a third test: I set the departure time to 8:00am (tomorrow morning), and the Off-Peak End Time to 10pm. I bet that charging will start at around 9:15, and end just before 10pm tonight.

This is very confusing, and not really as explained in the manual. Or at least it's not the way I understood it from the manual. But I think I got it now.
It somewhat explains why you can't set a departure time without selecting OFF-Peak or Precondition.
Are you guys seeing the same behavior?

My third test ended exactly as predicted: the charging started at around 9:15 and ended shortly before 10:00, with the departure time set to 10 hours later (next morning).

That's been my experience in three weeks of owning the car... "Scheduled charging" = "Start charging at this time" and "Off peak" = "finish charging at this time".

My general use case is to set the off-peak time and departure/precondition to the same time (0445 off peak every day, 0445 departure weekdays) and both usually finish about 15 minutes ahead of time. My actual "super off peak" time ends at 0700 so if I weren't leaving till after that, I'd use that as the end time.

I agree that the UI for this is poor and should have better explanations, and more options than just "weekdays" or "all week". But for the latter I'm not sure whether a third-party app purchase/subscription is worth it just to manage different schedules vs. just doing it myself manually, especially since there will be days that will result in manual overrides anyway.

It would also be nice if the "precondition" setting let you input the desired HVAC settings rather than just using "last used".

Yes, I will be doing the same thing: setting departure time and off-peak end time to be the same should work!

 

[jcanoe]

Scheduled Departure Preconditioning weekdays or every day is mostly a benefit for passenger comfort in winter. In spring, summer and early fall there is no need to precondition the Tesla Model Y in the A.M. before driving. In winter temperatures some amount of battery warming via stator heating will take place during preconditioning, as required, but only in colder weather.

In the current Tesla software the amount of battery warming that will be performed in colder temperatures is limited to save energy when compared to battery warming that was performed under older releases of the Tesla software. In the past, one of the benefits of extended battery warming was to restore at least partial level of regenerative braking in cold weather.

Tesla now provides a setting under Pedals and Steering to automatically apply (blend) the friction brakes when regenerative braking is reduced or unavailable due to low battery temperature or a high state of charge in the battery. When you enable the blended friction braking the Tesla Model Y will slow/brake with no difference in perceived regenerative braking even in cold weather with no preconditioning.

This saves energy and reduces the time need to precondition the Tesla Model Y (Preconditioning is now mostly to warm the passenger cabin before driving.) If the battery temperature is below optimal while driving the Tesla Model Y will display a blue snowflake. For most driving you will not notice any difference in available power when the blue snowflake is displayed. Prolonging preconditioning before driving will not continue to warm the battery more than the nominal degree of battery warming that is performed.

 

[ewoodrick]

If all else fails. Read the manual. It took me less than a minute to find a simplified English version of what it seems to take you a long time to find.

Model Y Owner's Manual | Tesla

Learn how to schedule charging and departure times.

www.tesla.com

• Use Scheduled Charging to specify a daily time in which you want Model Y to start charging.
• Use Scheduled Departure to set a daily time when you want Model Y to be ready to drive. Model Y automatically calculates when it needs to start preconditioning and/or charging. This ensures that charging is complete and/or the cabin climate and Battery are preconditioned by your departure time.

 

[jcanoe]

In the Tesla Model Y Scheduled Charging, Scheduled Departure (with or without charging) are an unholy mess. There are many things that can disrupt these settings.

Examples:

If two phones have the Tesla app installed, with access to the same Tesla vehicle then Scheduled Departure will take place even if disabled from one phone or in the Tesla vehicle settings.

If you want to use Scheduled Departure -Charging you need to enter the end (but not the beginning) of a real or imaginary off-peak utility rate window so that the Tesla charging system can determine when charging needs to be completed.

If you have multiple off-peak windows within a 24 hour period then you must pick one window to the exclusion of any other off-peak windows (else use third party software.)

Once you have setup Scheduled Charging or Scheduled Departure - Charging (for an end of off-peak window) with the way you want if you need to turn off, change or remove these settings is it best to remove Scheduled Charging/ Scheduled Departure settings, re-enter the settings later. (I'm not sure if there is a simple, reliable means of overriding Scheduled Charging/Schedule Departure Charging for a single charging session at the Home, Work or Other location. In GM plug-in vehicles, for instance, if you squeeze the trigger button on the J1772 charging connector twice this overrides any Scheduled Charging settings for one charging session.)

 

[ewoodrick]

In the Tesla Model Y Scheduled Charging, Scheduled Departure (with or without charging) are an unholy mess. There are many things that can disrupt these settings.

Examples:

If two phones have the Tesla app installed, with access to the same Tesla vehicle then Scheduled Departure will take place even if disabled from one phone or in the Tesla vehicle settings.

If you want to use Scheduled Departure -Charging you need to enter the end (but not the beginning) of a real or imaginary off-peak utility rate window so that the Tesla charging system can determine when charging needs to be completed.

If you have multiple off-peak windows within a 24 hour period then you must pick one window to the exclusion of any other off-peak windows (else use third party software.)

The reason why you call it a mess is because you are trying to use it for something that it is not and you are too worried about your battery.

Scheduled Departure does not think about nor care about time of day rates. It's intent ONLY is to make sure that the car is preconditioned for jumping in on a cold winters day.

Schedule charging is for time of day rates and is intended to be the evening time at which time the rates decrease. It assumes that you are charging at a rate for which the battery will be full before rates increase.


Pretty simple. It's when you try to go beyond what it is intended for that it just may not work.

 

[jcanoe]

The reason why you call it a mess is because you are trying to use it for something that it is not and you are too worried about your battery.

Scheduled Departure does not think about nor care about time of day rates. It's intent ONLY is to make sure that the car is preconditioned for jumping in on a cold winters day.

Schedule charging is for time of day rates and is intended to be the evening time at which time the rates decrease. It assumes that you are charging at a rate for which the battery will be full before rates increase.


Pretty simple. It's when you try to go beyond what it is intended for that it just may not work.

Currently I don't use these settings. I found, when I did experiment, that these functions were very fragile. (The Tesla Scheduled Charging and Scheduled Departure Charging settings do not take well to accepting changes once you have Scheduled Charging or Scheduled Departure Charging working.)

 

[flixden]

If all else fails. Read the manual. It took me less than a minute to find a simplified English version of what it seems to take you a long time to find.

Model Y Owner's Manual | Tesla

Learn how to schedule charging and departure times.

www.tesla.com

• Use Scheduled Charging to specify a daily time in which you want Model Y to start charging.
• Use Scheduled Departure to set a daily time when you want Model Y to be ready to drive. Model Y automatically calculates when it needs to start preconditioning and/or charging. This ensures that charging is complete and/or the cabin climate and Battery are preconditioned by your departure time.

I have read that. My point is that the manual is not clear on what these settings really do. At least not to me ...

 

[flixden]

The reason why you call it a mess is because you are trying to use it for something that it is not and you are too worried about your battery.

Scheduled Departure does not think about nor care about time of day rates. It's intent ONLY is to make sure that the car is preconditioned for jumping in on a cold winters day.

Schedule charging is for time of day rates and is intended to be the evening time at which time the rates decrease. It assumes that you are charging at a rate for which the battery will be full before rates increase.


Pretty simple. It's when you try to go beyond what it is intended for that it just may not work.

I think you are right on with this statement.
It's just that when you fully understand how it really works and what these settings do, you can use it for things that it wasn't really meant to do in the first place.
For example, we have the same electricity rate at all times, but I can use this setting to actually make the car start charging before my departure time (to be charged when I leave), instead of immediately. Nothing wrong with that if it works for me ...

 

[ewoodrick]

I think you are right on with this statement.
It's just that when you fully understand how it really works and what these settings do, you can use it for things that it wasn't really meant to do in the first place.
For example, we have the same electricity rate at all times, but I can use this setting to actually make the car start charging before my departure time (to be charged when I leave), instead of immediately. Nothing wrong with that if it works for me ...

And what you are needing to use is Scheduled Departure then. The car will make sure that it is charged. then. Don't worry about Scheduled Charging.

 

[flixden]

And what you are needing to use is Scheduled Departure then. The car will make sure that it is charged. then. Don't worry about Scheduled Charging.

The idea is to keep the car at a lower SOC for as long as possible, especially when one is planning to charge to 90% or above for a trip.
But I get your point: the few hours saved here and there probably won't make much of a difference in the overall big picture, unless this is done every day. At least I think that's your point, and you are probably correct here as well.
As an engineer myself, I do like to really understand how those things work, so that hopefully kinda explains why I am trying to get to the bottom of this. It's fun for me.

 

[jcanoe]

Before Tesla updated Scheduled Departure - Charging there was a fixed charging end time of 0600 (local time.) This early A.M. charging window end time was selected as the having the least impact to the utility grid. Inflexible but consistently worked.

 

[ewoodrick]

The idea is to keep the car at a lower SOC for as long as possible, especially when one is planning to charge to 90% or above for a trip.
But I get your point: the few hours saved here and there probably won't make much of a difference in the overall big picture, unless this is done every day. At least I think that's your point, and you are probably correct here as well.
As an engineer myself, I do like to really understand how those things work, so that hopefully kinda explains why I am trying to get to the bottom of this. It's fun for me.

That's not the Tesla recommendation. Tesla really says very little about the daily SoC, except that there are recommended hash marks for daily charging level.
Tesla doesn't say anything about charging to 100% except that it is okay and expected for trips. It also will let you know if you leave it at 100% (not 95%) that you shouldn't constantly do it.

Yes, there are GENERIC studies that indicate that batteries left at 100% for long periods of time can have degradation. But look at the studies, I think it is maybe 10-20% if held at 100% FOR A YEAR!! But yet the forum experts extract that to minutes.

 

[fholbert]

If all else fails. Read the manual. It took me less than a minute to find a simplified English version of what it seems to take you a long time to find.

• Use Scheduled Departure to set a daily time when you want Model Y to be ready to drive. Model Y automatically calculates when it needs to start preconditioning and/or charging. This ensures that charging is complete and/or the cabin climate and Battery are preconditioned by your departure time.

Yea, that doesn’t work.

I use about 42% of my charge each weekday.

I started using Scheduled Departure two weeks ago. I set it up for 80% and a 3:30 am departure time.​

​

It typically starts charging at 12:00 to 12:45 am, my off-peak starts at 9:00pm. When I get to the car at 3:45am it‘s still charging and at 68% to 74%. As the week progresses the charge is lower and lower.​

​

I‘m using the Tesla L2 charger on a 240v 50a circuit. The car is configured for 40a using the 80% rule. Yes the wires are properly torqued. I’ve even measured the temperature at the connections making sure they weren’t getting hot.​

Scheduled Departure doesn’t work for me. If someone has an idea, I’m listening.

 

[ewoodrick]

Yea, that doesn’t work.

I use about 42% of my charge each weekday.

I started using Scheduled Departure two weeks ago. I set it up for 80% and a 3:30 am departure time.​

​

It typically starts charging at 12:00 to 12:45 am, my off-peak starts at 9:00pm. When I get to the car at 3:45am it‘s still charging and at 68% to 74%. As the week progresses the charge is lower and lower.​

​

I‘m using the Tesla L2 charger on a 240v 50a circuit. The car is configured for 40a using the 80% rule. Yes the wires are properly torqued. I’ve even measured the temperature at the connections making sure they weren’t getting hot.​

Scheduled Departure doesn’t work for me.

Guessing that you are in the California version of Ontario CA (and because you leave so early to evidently fight traffic), your need is for Scheduled Charging, so that you can use the cheap rates. Your car doesn't need to be preconditioned. to travel.

 

[fholbert]

Guessing that you are in the California version of Ontario CA (and because you leave so early to evidently fight traffic), your need is for Scheduled Charging, so that you can use the cheap rates. Your car doesn't need to be preconditioned. to travel.

True and true. Except, I don’t fight traffic, no need at 3:45am . I have a lot of freedom on my start time and work on site 5:00am to noon, a conference call or two after I get home.

I‘ve wondered if preconditioning was doing any good in SoCal. I should go back to Scheduled Charging.

 

[ccaffeine]

What I don't get is that the app already lets us enter peak / mid peak / off peak times, the app KNOWS the electricity rates and timing for specific charge locations. Why is it this difficult? I should have options as such:

1. what is your departure time and desired SOC? e.g. 7pm, 80% SOC
2. charge only during [ ] off peak [ ] mid peak [ ] peak (chose one or more)
3. the app will charge only during the periods you select with the goal of reaching desired SOC by the departure time

It's not rocket science. Task two of your programmers on this, what the hell Tesla

 

[Rocky_H]

I started using Scheduled Departure two weeks ago. I set it up for 80% and a 3:30 am departure time.

Here's where the description of these functions in the interface is so muddled and terrible. You would be sensible in thinking this "Departure time" would be when it would be charged and ready to go, but it doesn't have to do with charging at all. It is for pre-warming or pre-cooling the cabin for your comfort. So that's why it's not meeting your charge limit.

The other two functions do have to do with charging:
1. Start time (obvious and sensible name)
2. Off peak (misleading name. This actually means charging end time.)

And you can only choose one of those two.

 

[jjrandorin]

I‘ve wondered if preconditioning was doing any good in SoCal. I should go back to Scheduled Charging.

Think of pre conditioning as HVAC for the cabin, and dont think of it as having to do anything at all with the battery. Thats not exactly accurate, but for thinking about whats happening, its probably the best thing to think about.

I personally dont like scheduled departure, I use scheduled charging to start my charge at 3am every morning, as there isnt any circumstance where starting at 3am doesnt complete my charge to my desired charge level before I get in the car to drive into the office.

If I were in your shoes I would probably use scheduled charging and start it at 11pm or midnight.

Im also not into "omg the battttterrrrrryyyyyy?!?!?!?!?!?!" like so many people are, here, so I am not trying to "stay at 52.;23421512% and finish charging 42 seconds before I want to drive out the door" (heh).

For me, Finishing charging within an hour or two of when I want to leave is fine, and as for conditioning the cabin, I do that manually by turning on climate using my phone, while I am fixing my cup of coffee to go in the kitchen. It takes about 5 minutes for the climate control to condition the cabin to my desired temperature with the car parked in my garage so I dont see any need to try to automate that, and I am not concerned in the slightest about battery heating for driving.