Any way to set charging ending time?

[iwannam3]

When I want to charge to 100% for a trip I have to guess how long it will take and set the start time. I want to minimize the time it sits at 100%. It would be better if I could set the time when I wanted it 100% and let the car figure out when to start charging. Or am I too concerned about the time at 100% degrading the battery?

 

[Getlib]

You're right and wrong.
You're right It would be better if we could set a finish charging time, even a finish estimate time.
You're wrong to worry about it being at 100% for a few hours.

 

[TT97]

There are some third party apps that can stop charging but none that I know of that will calculate the charge time and start for a anticipated end time. I suppose the issue is that there are variable that could affect the charge rate which makes it difficult to predict. Also, if you do not charge 100% often (which you shouldn't be), those last few percentage points to charge are very slow and unpredictable (I believe it has to do with the batteries re-balancing when approaching 100%).

What I do in the times I do want to charge to 100% is this. The night before, I start the charge at 100% and then reduce to 90% while charging and note the difference in time between the two. I then leave the car at 90% until before I need to leave and then do a second charge in the morning to get to 100% (or close to it). I would recommend adding 30 minutes to the time you calculated but in the end, even if you charge to "only" 98%, that is six miles difference.

 

[iwannam3]

There are some third party apps that can stop charging but none that I know of that will calculate the charge time and start for a anticipated end time. I suppose the issue is that there are variable that could affect the charge rate which makes it difficult to predict.

The car knows the battery temperature and all the other factors involved with charging and should be the best in calculating time to charge while monitoring it and adjusting as needed.

 

[TT97]

The car knows the battery temperature and all the other factors involved with charging and should be the best in calculating time to charge while monitoring it and adjusting as needed.

Yes, but it will not know the external temperature affecting battery temperature nor will it know any fluctuations in the voltage. Unless it is not charging at max amp, it can't speed up the charging to finish in time if it falls behind.

 

[ewoodrick]

When I want to charge to 100% for a trip I have to guess how long it will take and set the start time. I want to minimize the time it sits at 100%. It would be better if I could set the time when I wanted it 100% and let the car figure out when to start charging. Or am I too concerned about the time at 100% degrading the battery?

You're too concerned. It isn't a problem to leave it at 100% for a little bit. One of the studies that everybody freaks out about is when the battery was left at 100% for a year, there was some degradation.

Charge to full and enjoy the trip!

 

[BerTX]

If you have an Android phone, then the Dashboard for Tesla app can do these things quite well.

If you have an IOS phone, I'm sorry.

 

[TT97]

If you have an Android phone, then the Dashboard for Tesla app can do these things quite well.

If you have an IOS phone, I'm sorry.

How does it calculate the charge rate? Does it take the variables into account for the charging time or is it just a set %/miles per hour? Does it take into account 90-100% is significantly slower rate than up to 90%? (Especially 95%+)

 

[chronopc]

If you have an Android phone, then the Dashboard for Tesla app can do these things quite well.

If you have an IOS phone, I'm sorry.

Have you noticed any increase in phantom drain from using Dashboard for Tesla?

 

[BerTX]

How does it calculate the charge rate? Does it take the variables into account for the charging time or is it just a set %/miles per hour? Does it take into account 90-100% is significantly slower rate than up to 90%? (Especially 95%+)

It depends. The most accurate way is to allow the car to start and stop charging during the charge cycle and tell it the charging source parameters. It will estimate charge starting time and begin charging early to assess the actual charge rate. It will then shut off and begin charging again at a more accurate start time. All this is within a charge time window to avoid TOU conflicts.

If you don't like the starting and stopping, it will just use the estimate it calculates.

Yes, all of this is based on charging curves for the particular vehicle configuration.

 

[BerTX]

Have you noticed any increase in phantom drain from using Dashboard for Tesla?

I have not noticed any issues. Unless it is using the charging features, it shouldn't wake the car any more than the Tesla app, but I don't know. Of course, when using the charging features, it is plugged in.

 

[pcons]

I find it funny how people always say that the calculations to estimate a set finished charge time are too complicated and there are too many variables. The engineers at tesla are pretty smart, and it's really not a difficult thing to figure out. They have all the sensors available to determine outside temp, charge current and voltage available from the evse, battery temp, etc, etc.

Even now when I plug the car in and have delayed charging on, the car detects the voltage and max current from my evse. The battery temp is known, the outside temp can be monitored, and it's not going to change drastically (though battery temp is all you really need). It's then a pretty simple calculation to estimate when to start the charge to finish by a certain time...

Is it going to be accurate down to the minute? No, is it possible? Of course.....anyone who says it isn't, then tell me why I could do this on my 2014 volt, 2017 volt and my wife's 2017 bolt? Unless GM has smarter people than Tesla....which I doubt since there are smart people at both companies.

Now as to why tesla hasn't implemented this feature, your guess is as good as mine. Since leaving on a warm battery is the best setup it's a no brainer to me that this should be a feature...but my name ain't Elon Musk, so there isn't much I can do about it

 

[iwannam3]

Since leaving on a warm battery is the best setup it's a no brainer to me that this should be a feature...but my name ain't Elon Musk, so there isn't much I can do about it

Hadn't thought of that as a feature, but it would be a good one. I find regen limited by battery temp when charging to a lower percent even when the garage is 50 degrees. I did wonder how to warm a battery before leaving.

 

[ZoomsansVroom]

OK, so I am in a similar boat. I'd rather charge at work, as our rate is 1/3 of my home rate, but I MUST never charge while the line is operating, or during on-peak hours - the increased demand charge gets rather ugly.

Could I set the car to only charge during certain hours? Can I set it to not charge until I tell it to, even if its plugged in?

I'll have it plugged in, at home, just to warm up the cabin, etc.

 

[duanra]

I don't think it is always easy to estimate what time charging will be complete.

If you charge in very cold temp. 1 st the battery has to warm up so it gives you a non realistic estimate. Than when it is warm enough, it gives a much shorter time...and it starts to cool off agsin and the charging time goes through the roof agsin...so so much for your estimate...

 

[Rottenapplr]

I was surprised tesla doesn’t support native precondition. I was expecting the car to warm the cabin at 7am before I leave for work at 715.

 

[ngogas]

Why do you baby the battery. Just charge it to 100 and go whenever you need to. You are over thinking it.

 

[David99]

Dashboard for Tesla does that really well. I have been using it since it came out. Setting the end time for the charge process is really how it should be. It helps battery health in general and as a nice side effect the battery is warmer when you leave in the morning.