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frustrating tesla scheduled charging explanation

everydaychris

Member
Feb 10, 2020
682
376
CA
So it should be simple right?

I switched my charging at home to scheduled departure by 4 AM.

However, sometimes when I plug in my Tesla, today, at 3 PM, it started charging. I thought it would possibly stop at 4 PM, when my rates are the highest, but it didn't!

Does anyone know what I'm doing wrong? I know there's a section of choosing when you're off peak time ends or something and I never really understood that either.

I also see a scheduled charge time where you can manually set it to charge however I thought Tesla's software was more advanced than that haha

Thanks !
 
Oct 3, 2020
205
241
Seattle
The scheduled departure feature does not factor in your utility rates to avoid charging during peak times. It will start the charge based on your current SoC, charge setpoint, selected charge rate, and departure time.
 

everydaychris

Member
Feb 10, 2020
682
376
CA
The scheduled departure feature does not factor in your utility rates to avoid charging during peak times. It will start the charge based on your current SoC, charge setpoint, selected charge rate, and departure time.
Makes no sense still as I had 61% battery and I set it to 80% charge with a departure time of 4 AM. 12 hours later after I plugged it in lol. So weird..
 
Oct 3, 2020
205
241
Seattle
Makes no sense still as I had 61% battery and I set it to 80% charge with a departure time of 4 AM. 12 hours later after I plugged it in lol. So weird..

Someone can correct me if I’m wrong, but I believe that it will charge it immediately to some SoC value before it stops and waits to charge the rest of the way. A setpoint of 80% may be low enough that it charges to setpoint immediately, without stopping to wait at all. Only when the setpoint is say 100% does it wait to charge that last 10% a few hours before departure.

I think the reasoning is worst case scenario driven.. what if the power is unavailable several hours from the point it’s plugged in due to a power outage or an unexpected slow charge rate.
 
Last edited:

srlawren

Active Member
Aug 3, 2020
1,134
767
Vancouver, BC, Canada, Eh?
I switched my charging at home to scheduled departure by 4 AM.
However, sometimes when I plug in my Tesla, today, at 3 PM, it started charging. I thought it would possibly stop at 4 PM, when my rates are the highest, but it didn't!
Makes no sense still as I had 61% battery and I set it to 80% charge with a departure time of 4 AM. 12 hours later after I plugged it in lol. So weird..

@everydaychris sorry if you've already mentioned this and I missed it, but are you charging from a "regular" wall socket (5-15 socket), or something quicker? I've noted that on regular charging (all we've done so far), our LR charges at about 1.5% (or slightly less) per hour of charging. So if you plugged in at 3pm and wanted to depart at 4am, that would give you up to 13 hours of charging, during which time you need to make up about 19%. 19% needed / ~1.5% per hour = ~12.67 hours, which with a margin of error would basically take up your entire 13 hour available window just trying to get up to the charge limit point of 80% SoC.

So if you are charging via regular 5-15 wall socket, the car is behaving as it should in order to get you to 80% by 4am. If you're charging with something faster, then obviously my rough calculations are no longer valid.
 

everydaychris

Member
Feb 10, 2020
682
376
CA
Thanks for the tips! It's a tesla wall charger!

I believe I found my answer after toying with the settings in the car menu.

When you adjust the settings for off peak charging, it asks when it ends. I put 4 PM and I believe it stops charging at 4:01 pm.

When I changed it to let's say 5 pm, it automatically started charging, however when I changed it to 3:45 PM it went to scheduled charging.

My highest rates are between 4-9 PM. This means, I set my off peak charging to end at 3:45 PM and my scheduled departure time at 4 AM.

The car should start charging according to how much battery I have in my car and when I need to depart and it should be after my highest rates ending at 9PM as it shouldn't take 7 hours to charge my car even if it's at zero with a Tesla wall charger.

Hope that cleared some confusion. I need to do a Youtube video on this lol.
 

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