Is Scheduled Departure Buggy?

[mathewparet@gm]

I used scheduled departure for the first time. I set my off peak end time as 6am and departure time as 6:15 am. Off Peak charging is enabled. This is set in the Schedule > Departure screen.

My actual off peak time is 10pm-12am and then 6am to 7am. From 12am to 6am is super off peak time. This is set in the Charge Stats > Settings screen.


But my car started charging only at about 12:30 and finished charging at 6:40am (that is after the scheduled departure time). The car was plugged in at 24% and charged till 100% at 32amps single phase.

Is this a bug?

How do I make sure my car is always ready by 6 or 6:15am?

Model Y RWD LFP.

 

[bcarp]

I've not had that problem, but that's a fairly long slow charge & the car probably misjudged the required start time. The cell balancing right at the end as it approaches 100% can be quite variable in timing too. Give it another go, but perhaps with a shorter charge duration (say, from 60-80%) & see what happens.

 

[cafz]

Yeah, I've not had that problem but I typically only charge to 70% - 90% depending on how much juice I need.

As @bcarp said you'll probably find it was cell balancing and it was may have been at 99% already by your departure time. The other possibility is that the grid voltage dropped significantly after it had started charging.

 

[mathewparet@gm]

Yeah, I've not had that problem but I typically only charge to 70% - 90% depending on how much juice I need.

As @bcarp said you'll probably find it was cell balancing and it was may have been at 99% already by your departure time. The other possibility is that the grid voltage dropped significantly after it had started

I use Teslascope to track usage. I can confirm that:

1. The voltage from the grid didn't drop at all.
2. I can see the car was at 99% since 6:24 till 6:41. This might be cell balancing. But even then it reached 99% only at 6:24 while my departure time was set to 6:15.

Does this auto fix over time (like once the car studies my charging behaviour)?

 

[doggy1]

LFP charging is always harder to predict because of the flatter curve. It will also depend how balanced the cells are (in other words, how often recently taken to 100%). I'm surprised you are worried about 1% SOC- must have had a very tight trip planned.

 

[mathewparet@gm]

in other words, how often recently taken to 100%

I charge 100% daily. But not all days does my charging start at 20. Most days I'd use hardly 5-10%

 

[father_of_6]

I think the issue is trying to use both scheduled departure and scheduled charging.

I've been using scheduled departure for a few months with preconditioning a half hour after off-peak ends. It's worked reliably for me.

 

[tyrotex]

I used scheduled departure for the first time. I set my off peak end time as 6am and departure time as 6:15 am. Off Peak charging is enabled. This is set in the Schedule > Departure screen.

My actual off peak time is 10pm-12am and then 6am to 7am. From 12am to 6am is super off peak time. This is set in the Charge Stats > Settings screen.


But my car started charging only at about 12:30 and finished charging at 6:40am (that is after the scheduled departure time). The car was plugged in at 24% and charged till 100% at 32amps single phase.

Is this a bug?

How do I make sure my car is always ready by 6 or 6:15am?

Model Y RWD LFP.

Rather than the Scheduled Departure setting, I think it is more some limitation on the Off-Peak Charging.
It seems to be just a case of not being able to complete the charge (fully) by 0600. See the note at the end of the manual Charging>Scheduled Charging & Scheduled departure: "Once charging has started and there is not enough time to complete charging during off-peak hours, charging continues until the charge limit is reached."
Unfortunately, there's no way to schedule a charging start time with a Tesla. Given that your off-peak starts at 2200, you could set the Off-Peak Charging time to end earlier. I don't believe it has to line up exactly with your Scheduled Departure time.
I also believe that the settings in Charge Stats are purely for calculation of the displayed Cost or Petrol Savings. As far as I know, they have no impact on the charging behaviour of the car.
But as other users have commented above, the final 1% for cell balancing (which seems to take ~30mins) shouldn't be an issue. It might have a slight effect on the displayed range remaining during your trip, but your drive would have to be very tight if you feel you really need it.
Also note that the preconditioning will use some of the available charger power. In my M3, it sometimes consumes ~3.5kWh and takes 45 minutes, but that's in a colder place than where you are. So what charger you are using (7.4kW, 3.5kW or 2.4kW) will have a large impact on how long a charging window you might need.
Just play with the times for a while and see how it goes.

 

[Max Spaghetti]

I only sometimes use scheduled departure because, as noted above, it is not great at predicting charge timing. I find I can better take advantage of off-peak rates by using scheduled start time (12:00am super-off-peak in my case), and manually moving it back if I calculate I'll need a longer charger before departure.

For example, if I need a 7 hour charge and I'm leaving after 7am, then leave it as is, but if I'm leaving at 5am, then I'll set it to start charging at 10pm instead. I can pretty easily calculate in my head: my 15A/230V UMC will charge my LFP battery about 33% in 6 hours. Call it 5% per hour for a rough calc.

I'm also seen comments that using scheduled departure prevents the vehicle from deep sleep, but I don't know much about that. The other disadvantage of scheduled start time is you don't get the option to automatically pre-condition prior to departure. I get around that by using automations in my iPhone.

 

[Vostok]

Unfortunately, there's no way to schedule a charging start time with a Tesla.

Huh?



Open App.

• Scroll down to Schedule
• select Charge tab
• Turn on Schedule Charging
• enter time to Start Charging At

Charging will commence at the nominated time and stop at the charge level you’ve set on the main screen of the App.

 

[mathewparet@gm]

I think the issue is trying to use both scheduled departure and scheduled charging.

I've been using scheduled departure for a few months with preconditioning a half hour after off-peak ends. It's worked reliably for me.

I didn't think that was possible. I thought it was either or.

 

[mathewparet@gm]

Meanwhile, I have another question - Yesterday I was driving from Manly to Jenolan Caves. About a few KMs just before reaching Jenolan caves (when the steep downhill started), I got an icon on my screen that said that said this:

This seems odd since I was driving continuously from Sydney so I think the battery temperature shouldn't be low. Also, it had reached 38% so SOC isn't low either. Also the ambient temp was 20c which I don't think is cold.

I've seen this notification at various times and had noticed it since the first week. Is this expected? or should I call Tesla Service?

Even tough I saw this message the battery still charged about 1-2% during the down hill due to re-generative braking. So I am a bit confused.

 

[fholbert]

Unfortunately, there's no way to schedule a charging start time with a Tesla.

Sure there is, look at the screen that comes up when you plug in.

 

[bcarp]

LFP charging is always harder to predict because of the flatter curve.

I think this is the crux.

It is possible to schedule departure. That’s just a preconditioning of the cabin and systems ready to drive off.

Separate to this, it’s possible to schedule either a start charging time (“Schedule Charging”) or an end charging time (“Off-Peak Charge”). It’s not possible to set both a start and finish time at the car or app itself, although this can be achieved by programming a Tesla Wall Connector separately.

The OP has chosen an end charging time of 6am. The car predicted it would need 5.5hrs to charge, so started at 12:30am. However, because the car can only measure car battery voltage, it has to use this to estimate the actual amount of juice in the battery & how much it will need to put it. With LFP, there is reportedly an imprecise correlation between voltage and stored energy, so in this situation, the car estimated wrongly & continued its charging until it finally finished at 6:40am.

I think the schedule departure setting has nothing to do with the described problem. If I needed to leave at 6:15 & the car said 99%, I’d be unplugging and driving right off.

 

[cafz]

I'm also seen comments that using scheduled departure prevents the vehicle from deep sleep, but I don't know much about that.

It definitely does not.

 

[cafz]

This seems odd since I was driving continuously from Sydney so I think the battery temperature shouldn't be low. Also, it had reached 38% so SOC isn't low either. Also the ambient temp was 20c which I don't think is cold.

I've seen this notification at various times and had noticed it since the first week. Is this expected? or should I call Tesla Service?

Even tough I saw this message the battery still charged about 1-2% during the down hill due to re-generative braking. So I am a bit confused.

It also comes up when a lot of regen has been done recently - possibly the opposite problem (the battery getting too hot)?

I don't see that notification much in the LR, but maybe others with the RWD (LFP battery) can comment.

You can still see it has some regen capacity - the dotted part of the regen graph at the top shows the "unavailable" portion. Looks like you have more than half the maximum available when that photo was taken.

 

[Onshore]

But even then it reached 99% only at 6:24 while my departure time was set to 6:15.

Does this auto fix over time (like once the car studies my charging behaviour)?

Thats pretty close, especially for an LFP car where there’s more guesswork involved in measuring the SOC at the start of charging which was estimated at 24% but in reality +/- 5%

It would have been 98% at the targeted time. That’s pretty good. Not seeing a problem here. There’s estimation involved and thats pretty accurate for a long charge of an LFP

 

[mathewparet@gm]

Thanks everyone for the clarifications. Have a nice week.

 

[tyrotex]

Huh?

View attachment 991930

Open App.

• Scroll down to Schedule
• select Charge tab
• Turn on Schedule Charging
• enter time to Start Charging At

Charging will commence at the nominated time and stop at the charge level you’ve set on the main screen of the App.

Of course. I was completely wrong about this aspect.
I became confused when reading the manual's description about what is and isn't available in conjunction with Scheduled Charging.
Apologies for posting incorrect information.