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Battery drain while parked or car in storage

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I left my car at DFW for three weeks. I left it at 70% but I turned off Sentry mode and overheat protection. I also didn't check in on my car very often, perhaps once a week. It was the first time ever leaving and I was concerned, but in the end I lost 1% of charge.

I wanted to leave Sentry on but decide I lived for decades without it. I also took my time and found a fairly safe spot to park where the lanes were wide and the change of door dings was not a concern.

I think this 1% loss over three weeks shows that the car never actively heats or cools the traction battery when not connected to shore power, even though the owners manual implies it does. All evidence points to traction battery heating/cooling only occurs (if required) when the owner preconditions the cabin while not connected to wall power. If anyone has proof of heating or cooling while parked and not connected to wall power, I have not found it.
 
Based on the latest info I've read (quite a bit), what I'd LIKE to solve your 'problem' this way: Leave battery charged at 60%, disconnect rear seat connector (contactor), close all windows and doors, lock car with frunk open, remove the 12V battery, close frunk, and keep 12V battery charged at home (as suggested by another member). Having said that, I don't know if you can do that, since the procedure to change the 12V battery asks you to leave 2 windows and 2 doors open. But on the other hand, if your car loses the 12V battery while locked, you can open the frunk thru the tow-hook cover (there are 2 wires in there), then jump the battery (or install one), and then you can open doors, to reconnect seat connector. So not sure which is true. Ha ha. You could give it a test try, to find out: Disconnect the seat connector, and check if you can open windows and doors with the battery still connected (you should IMO). If you do, then you'd be in business to do what I suggested :). Good luck, and keep us posted on what you did.

If you wait until the car enters sleep state, you can remove the cable from the negative 12V battery terminal and the car will be shut down (ie.. contactors are open in sleep state and requires power from the 12V battery to close them). The best way to determine if the car is sleeping is listening for the clicking sound with your ear against the charge port door. When the clicking sound stops, the car is sleeping. When the car is awake, you can usually hear pump(s) running but not always (or maybe it is my bad hearing!). With the neg cable removed, you will not be able to enter the car/trunk/frunk so leave the frunk open or use the 9V battery trick to open it to reconnect the 12V cable. The only time you need to mess with the cable under the back seat is when you can't wait for the car to enter sleep state or the car won't enter sleep state for some reason. I recommend only momentarily lifting the connector under the back seat (wait about 10 seconds before reconnecting) as the car can not power back up because the 12V negative cable is not connected. In fact, on my Model 3 simply unlatching/re- latching the under seat connector lock works (ie no need to lift the connector).
 
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I left my car at DFW for three weeks. I left it at 70% but I turned off Sentry mode and overheat protection. I also didn't check in on my car very often, perhaps once a week. It was the first time ever leaving and I was concerned, but in the end I lost 1% of charge.

I wanted to leave Sentry on but decide I lived for decades without it. I also took my time and found a fairly safe spot to park where the lanes were wide and the change of door dings was not a concern.

At the Portland airport they have many AC plug ins for EVs in the parking garage. Last time I picked someone up at the airport (over a year ago) I parked in the garage there was a long row of Teslas plugged in.
 
At the Portland airport they have many AC plug ins for EVs in the parking garage. Last time I picked someone up at the airport (over a year ago) I parked in the garage there was a long row of Teslas plugged in.

DFW has Tesla chargers but they all have a one hour hour time limit. They have a concierge service where they will charge your car but it’s something like $20 a day.
 
Hey all,

I am losing about 10% of battery after I charge to about 80% and park up for 2 days. Is this normal? I do have sentry mode on, park in a garage around 65f. I feel its a little much, but not sure what others are seeing.

also took it on a drive about 75 miles and saw 100 miles of range lost. Moderate temps but mostly highway.
 
Hey all,

I am losing about 10% of battery after I charge to about 80% and park up for 2 days. Is this normal? I do have sentry mode on, park in a garage around 65f. I feel its a little much, but not sure what others are seeing.

also took it on a drive about 75 miles and saw 100 miles of range lost. Moderate temps but mostly highway.

yes that is normal and not much at all. what do you expect?
 
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As a data point to add: left my car at a parking lot near SFO for 7 days. Left Sentry mode on and the consumption was 7% per 24 hours on my 2020 Performance Model 3. I started at 80 percent and I knew it was relatively shorter trip so I knew I had enough. For a longer trip in the future I will be disabling Sentry mode and other phantom drains.
 
I left my car unused for about 10 days parked in a garage, mid 70F temperature, unplugged at 31% SOC and was left with 29% after 10 days. No Sentry Mode, Cabin Overheat On (fan-only, but in the garage, so stayed inactive).

Using TeslaMate to monitor. It seemed to wake up once a day for a few minutes for some reason (could be a TeslaMate artifact?). Every 2.5 days or so it would wake up for about 2.5 hours, presumably to top-off the 12V battery. The time duration between top-offs seemed to decrease as time went on, as only about 31 hours before the 4th top-off occurred, but about 60 hours before the 1st and 2nd top-offs occurred and then 48 hours between the 2nd and 3rd top-offs.
 
I think this 1% loss over three weeks shows that the car never actively heats or cools the traction battery when not connected to shore power, even though the owners manual implies it does. All evidence points to traction battery heating/cooling only occurs (if required) when the owner preconditions the cabin while not connected to wall power. If anyone has proof of heating or cooling while parked and not connected to wall power, I have not found it.
I don't think it implies no active cooling or heating. The battery is not at extremes in this situation. It would take a test at very cold and very hot temp to know what range it allows. I know the battery isn't supposed to be allowed to freeze, but it doesn't need to live at 72 degrees at all times.
 
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I don't think it implies no active cooling or heating. The battery is not at extremes in this situation. It would take a test at very cold and very hot temp to know what range it allows. I know the battery isn't supposed to be allowed to freeze, but it doesn't need to live at 72 degrees at all times.

i do think the battery does have active cooling but this probably only comes on above the hot limit (I think 50C or smth). This temperature isnt really reachable on most places on earth as the battery will always be a bit cooler than peak temp outside...
It certainly doesnt cool when the car is parked in 45C I can say that for sure.
 
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monitor. It seemed to wake up once a day for a few minutes for some reason (could be a TeslaMate artifact?). Every 2.5 days or so it would wake up for about 2.5 hours, presumably to top-off the 12V battery.
Interesting that your car goes so long between top ups. I think I have turned off everything that could drain energy, but it still only goes for a max of 24 hours or so between recharges of the 12V. (It is this recharge triggering wake up, because you can see it is triggered by a fairly specific voltage on the 12V battery monitor, consistently.)


I know the battery isn't supposed to be allowed to freeze, b
Is this true?
 
Interesting that your car goes so long between top ups. I think I have turned off everything that could drain energy, but it still only goes for a max of 24 hours or so between recharges of the 12V. (It is this recharge triggering wake up, because you can see it is triggered by a fairly specific voltage on the 12V battery monitor, consistently.)



Is this true?

maybe your 12V is getting depleted?
When my car was new it would wake up ever 2.5 days to top up the battery too. Now its every 1.5 days or so on a 2 year old battery. but the wake cycle is shorter i.e. 1h rather than 90min.
 
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I left my car unused for about 10 days parked in a garage, mid 70F temperature, unplugged at 31% SOC and was left with 29% after 10 days. No Sentry Mode, Cabin Overheat On (fan-only, but in the garage, so stayed inactive).

Using TeslaMate to monitor. It seemed to wake up once a day for a few minutes for some reason (could be a TeslaMate artifact?). Every 2.5 days or so it would wake up for about 2.5 hours, presumably to top-off the 12V battery. The time duration between top-offs seemed to decrease as time went on, as only about 31 hours before the 4th top-off occurred, but about 60 hours before the 1st and 2nd top-offs occurred and then 48 hours between the 2nd and 3rd top-offs.

I think the car also wakes up once a day to tune in the mothership and see if there is an update. I was watching network activity once when the car woke up and it briefly communicated with a server in the Bay Area then the car went back to sleep. The car was plugged in, but it hadn't been driven in a day or two.
 
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Just did some searches. It looks like freezing is ok. But doing any charging of a frozen lithium battery is very bad for it.
Yes. That is true. I am not aware of evidence suggesting any active conditioning of the battery, except perhaps for ridiculously extreme temperatures which are basically never encountered (I don’t what temps those would be). It seems counterproductive to spend any energy conditioning the battery, when it is unused.
maybe your 12V is getting depleted?
When my car was new it would wake up ever 2.5 days to top up the battery too. Now its every 1.5 days or so on a 2 year old battery. but the wake cycle is shorter i.e. 1h rather than 90min.

Yeah that is my theory! I guess I will find out when my 12V fails and I get to see the new interval. It’s either that or my standby drain is a few watts higher for whatever reason. Unfortunately there has not been any 12V monitoring data that has been shared by people with new batteries.
 
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Just did some searches. It looks like freezing is ok. But doing any charging of a frozen lithium battery is very bad for it.
And the manual says:
For better long-term performance, avoid exposing Model 3 to ambient temperatures above 140° F (60° C) or below -22° F (-30° C) for more than 24 hours at a time.
It does heat the battery before charging at low temperature. (And maybe cools it before charging at very high temperatures?)

But when not charging, it seems to be good between -30C and +60C.
 
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