A connected Model S is a happy Model S

[DrivingRockies]

Is a plugged in but not charging Tesla still a happy Tesla or is it indifferent until it drops below the set charge limit? Is there any benefit to leaving your car plugged in when you don't want to charge? As I mentioned in my original post, I don't charge at home. Is there any real reason to leave it plugged in in this case?

I don't know if there is a hard and fast answer to that. I've been unable to find anything other than the user manual. Any Tesla rep simply quotes that.

Perhaps see what the amperage draw is when plugged in, with and without the fan on. That might give an indication of something going on "behind the scene".

 

[jelloslug]

Remember "ABC":

Always
Be
Charging

 

[gavine]

I think the "happy Tesla" has to do with the 12v battery. If the HV battery is above the set limit while plugged-in, my guess is that the car will use the EVSE to top-off the 12v battery in order to keep the cycles shallow. This will preserve the 12v battery without drawing from the HV battery, thus minimizing vampire drain off of your range.

 

[gregd]

I think the "happy Tesla" has to do with the 12v battery. If the HV battery is above the set limit while plugged-in, my guess is that the car will use the EVSE to top-off the 12v battery in order to keep the cycles shallow. This will preserve the 12v battery without drawing from the HV battery, thus minimizing vampire drain off of your range.

That's what one would hope for, but apparently the 12v battery is on its own to power the internal systems when the main contactor is not engaged (i.e. when not driving or actively charging). Unfortunately, being plugged in doesn't appear to change that.

See the thread Near annual replacement of 12V battery is typical according to Tesla Service Tech for the details...

 

[Fiver]

After asking the service center, they said that really the only reason to plug in is to charge (or maintain charge). Nothing in the car uses "wall power" when plugged in but not charging.

/edit. It will use wall power when powered up though (like if the doors are open, HVAC is on), but once the doors are shut and the car is empty, the car shuts down, power switches open and current draw stops.

 

[AWDtsla]

Since this thread is back from the dead, my 2 cents:

My logging indicates that vampire drain increases quite a bit if you leave your Tesla plugged in. Almost like it knows it can't run out of juice. Car was plugged in while I was on vacation for ~6 days in a temperature controlled garage, should have been no reason for this. Approximately 40 rated miles were dropped from vampire usage during those 6 days. Repeating the experiment requires going on many more long vacations, so don't know when I'll do that.

 

[eprosenx]

Since this thread is back from the dead, my 2 cents:

My logging indicates that vampire drain increases quite a bit if you leave your Tesla plugged in. Almost like it knows it can't run out of juice. Car was plugged in while I was on vacation for ~6 days in a temperature controlled garage, should have been no reason for this. Approximately 40 rated miles were dropped from vampire usage during those 6 days. Repeating the experiment requires going on many more long vacations, so don't know when I'll do that.

I would not be surprised if Tesla takes advantage of plugged in cars to upload more telemetry data (i.e. like self driving machine learning stuff) back to the mothership. If you are plugged in you may care a lot less about vampire loss (you still pay for the power, but may not care compared to having your battery drain when not plugged in).

Also, maybe as folks suggest it gets more aggressive about battery temperature maintenance... When on wall power maybe it keeps the battery warm/cool so you are ready to go at an optimal state when you do decide to use the car?

It would be nice to have logging you could see about what it was doing...

 

[AWDtsla]

I would not be surprised if Tesla takes advantage of plugged in cars to upload more telemetry data (i.e. like self driving machine learning stuff) back to the mothership. If you are plugged in you may care a lot less about vampire loss (you still pay for the power, but may not care compared to having your battery drain when not plugged in).

Also, maybe as folks suggest it gets more aggressive about battery temperature maintenance... When on wall power maybe it keeps the battery warm/cool so you are ready to go at an optimal state when you do decide to use the car?

It would be nice to have logging you could see about what it was doing...

It's not warming or cooling the battery. Garage is temperature controlled. It's the normal draw from the car not sleeping.

 

[born2run]

Ok so I know this question is somewhat answered elsewhere, but finding a solid answer to it is challenging...I am going to be on vacation for about 8 days, need to move my Tesla model S out of my driveway (because it is getting repaved - I do not have a garage at home) and I am going to leave it in my work garage (where I have access to charging). What is the recommendation here? I typically charge to 80% daily - so should I just leave it unplugged, should I have my garage guys charge it a bit? I probably can't sit on the charger for 8 days straight (there are a few other Tesla's in this garage). Thanks in advance.

 

[David29]

I would suggest parking it and leaving it alone, so that you do not need to worry about other people finding it in the way or moving it.
You can check its battery state part-way through your vacation (4 or 5 days in) and if you are concerned, then ask someone to charge it. (You can unlock it via your phone, as long as the car and your phone are both in cellular range of their respective networks. that way you don't even need to leave a key.)
Caveat: This is based upon what have read and my own experience with leaving my car for a few days. I do not think I have ever left it for 8 days without charging. But I vividly recall Bjorn Nyland leaving his Model S for several weeks in the winter, unplugged, while he took a winter holiday vacation, and his car was fine.

 

[Fiver]

I would suggest parking it and leaving it alone, so that you do not need to worry about other people finding it in the way or moving it.
You can check its battery state part-way through your vacation (4 or 5 days in) and if you are concerned, then ask someone to charge it. (You can unlock it via your phone, as long as the car and your phone are both in cellular range of their respective networks. that way you don't even need to leave a key.)
Caveat: This is based upon what have read and my own experience with leaving my car for a few days. I do not think I have ever left it for 8 days without charging. But I vividly recall Bjorn Nyland leaving his Model S for several weeks in the winter, unplugged, while he took a winter holiday vacation, and his car was fine.

I've left my car unplugged for long periods with no ill harm. I'll charge to 90% and let it sit. The longest I've gone is 21 days, and it went from 90% to 40%. And that was with power saving off and always connected on. (And in winter).

Summer time, with the energy saving stuff turned on, you will be more then fine for 8 days if you start at 90%.

As long as it's out of the sun where cabin overheat protection might kick on you should be fine.

 

[Rocky_H]

.I am going to be on vacation for about 8 days

8 days is nothing. You don't need to do anything special for it. They sit for longer than that when they are transporting them by rail across the country.

 

[Lasttoy]

Thanks montgom for picture. I have printed out and hung on the door to remind me.

 

[Lasttoy]

Mine charges at high noon off my solar panels.
But
It stays plugged in as manual suggest.

 

[iCharge]

interesting thread, my MS has been sitting for last 10 days, without being plugged in, garage temp 40-50F, vampire drain is about 4 miles per day. I plan on charging it every week or so to 80%

 

[Canuck]

When I'm away from home at my cabin it's nice to be able to watch my wife's charging habits, which are not much different from her iPhone's charging habit (charge when low), so I just sent her a pic of the "A Happy Model S is a Plugged In Model S" card (which is what brought me here -- to find a copy to send to her). That card was sitting on the seat of my S when it arrived new coming up to 5 years now. Tesla stopped with those cards when the FUD folks turned their attention to electric cars are too much of a nuisance, you can brick the batteries if you don't charge them, the batteries burn in your garage while charging, and on the roads when they hit something, etc.

But now that Tesla is getting to the last part of: "First they ignore you, then they laugh at you, then they fight you, then you win" --- they should start putting the cards back on the seats.

 

[Fiver]

When I'm away from home at my cabin it's nice to be able to watch my wife's charging habits, which are not much different from her iPhone's charging habit (charge when low), so I just sent her a pic of the "A Happy Model S is a Plugged In Model S" card (which is what brought me here -- to find a copy to send to her). That card was sitting on the seat of my S when it arrived new coming up to 5 years now. Tesla stopped with those cards when the FUD folks turned their attention to electric cars are too much of a nuisance, you can brick the batteries if you don't charge them, the batteries burn in your garage while charging, and on the roads when they hit something, etc.

But now that Tesla is getting to the last part of: "First they ignore you, then they laugh at you, then they fight you, then you win" --- they should start putting the cards back on the seats.

Meh, my Model S lived its life unplugged unless it needed a charge and it's just as happy as any car that was left plugged in every possible second.

As long as you keep the charge between 20-90% the car really doesn't care if it's plugged in or not.

 

[Canuck]

Meh, my Model S lived its life unplugged unless it needed a charge and it's just as happy as any car that was left plugged in every possible second. As long as you keep the charge between 20-90% the car really doesn't care if it's plugged in or not.

Either your car defies science, or you don't believe in, or know, the science:

How to Prolong Lithium-based Batteries - Battery University

In particular:

Table 2: Cycle life as a function of depth of discharge.* A partial discharge reduces stress and prolongs battery life, so does a partial charge.

It's fine to say you don't care about a larger loss percentage. That makes sense to me since over the long run to some people it's not worth being concerned about. They may be on a lease, plan to trade it in after a few years, just not worth being bothered about since it's not all that much, etc.

But I'm talking about my cars here, and I want them to last as long as they can, and when I sell, I would like to leave a well-treated battery for the next person. You can do large rather than shallow charges, which science proves degrades the battery faster, but you can't say your car is "just as happy as any car left plugged in every possible second." Please read the science. That's clearly a false statement. Do you also deny climate change? Probably not, but if so, it's probably not worth debating this issue further with you since that will tell me all I need to know. But something tells me you can be persuaded by the science and it's very easy to test longevity by shallow vs. larger discharges -- that's been done in the labs and we know the result as a matter of fact. And that's why Tesla included the card in my car to always keep it plugged it s when at rest. Do the readers believe you or the science and Tesla?

By the way, what's your loss percentage? Mine is 4% after 120k km and 4.5 years. But I did a lot of full discharge/charges in the two years I had my car before a Supercharger was installed 1/2 way to my cabin -- so I no longer have to stress the battery as much. Still pretty impressive when I look at the stats.

 

[Fiver]

Either your car defies science, or you don't believe in, or know, the science:

How to Prolong Lithium-based Batteries - Battery University

In particular:



It's fine to say you don't care about a larger loss percentage. That makes sense to me since over the long run to some people it's not worth being concerned about. They may be on a lease, plan to trade it in after a few years, just not worth being bothered about since it's not all that much, etc.

But I'm talking about my cars here, and I want them to last as long as they can, and when I sell, I would like to leave a well-treated battery for the next person. You can do large rather than shallow charges, which science proves degrades the battery faster, but you can't say your car is "just as happy as any car left plugged in every possible second." Please read the science. That's clearly a false statement. Do you also deny climate change? Probably not, but if so, it's probably not worth debating this issue further with you since that will tell me all I need to know. But something tells me you can be persuaded by the science and it's very easy to test longevity by shallow vs. larger discharges -- that's been done in the labs and we know the result as a matter of fact. And that's why Tesla included the card in my car to always keep it plugged it s when at rest. Do the readers believe you or the science and Tesla?

By the way, what's your loss percentage? Mine is 4% after 120k km and 4.5 years. But I did a lot of full discharge/charges in the two years I had my car before a Supercharger was installed 1/2 way to my cabin -- so I no longer have to stress the battery as much. Still pretty impressive when I look at the stats.

90% charge is 225 miles of range, odo at 91k miles, car built Oct ‘13. Right in line with people who plug in every night and charge to 90% whenever possible. I don’t doubt the science, but if you follow the science you probably want facts. So here’s a hard fact: My car Is only plugged in when I need to charge, and it’s battery degradation is exactly the same as people who plug in every possible second.
Maybe in another 100k miles or 10 years this practice might be an issue, but I won’t have the car then. For the moment, it’s working just fine. (also I supercharge a lot)

 

[Rocky_H]

so I just sent her a pic of the "A Happy Model S is a Plugged In Model S" card

Like livin' on the edge, do you?