Let's talk about phantom drain

[Nobelcat]

I've seen other people discuss phantom drain on their CTs, but I haven't seen any discussion with specifics about what is normal and what isn't. Back in the day I'd read about people having a 2% drop per day and them being upset about it. I'm seeing more like a 10% per day drain.

I left my CT for just under 2 weeks in an underground garage with sentry turned off, no wifi or cellular coverage, and I wasn't in town to accidentally have the car see me as nearby. I came back and the car went from 80% SOC to dead zero. Tesla had to send out a tow truck to give me a jump start (which is funny since I gave away my 12v jumper when I got the CT, even though that would have saved me the 12v jump I got). Needed the jump in order to unlock the charge port to plug it back in to my L2 charger (even with the flap open, the CT wont accept a charger being plugged in).

*Since* then, I've added the truck to Tessie. Even today on 2024.8.12, I'm seeing 10kwatts of power over 18 hours of being idle. Or a few days ago, while camping, I had 30kwatts consumed over 48 hours of it being parked (though that's not a great example as I was frequently around the car).

More specifically, while camping outside the truck, even with my app closed to prevent it from seeing me nearby, I'd hear the high voltage system click off every 13 minutes. Very specifically 13 minutes. Same sound you'd hear when you plug it into a charger and the high voltage system switches from 800 volts to 400 volts. Then ~30 seconds later (I didn't time it), you'd hear the two clicks of it getting enabled again. What I think is: the truck is going into the proper idle state, and then it's being woken up for some reason.

I don't have a good way to confirm this, but I have a feeling that the car is keeping the battery pack warm for some reason. It's somewhat just a guess with a few other signs that lead me to that feeling, but very much nothing formal. So, are other people experiencing the same? And any suggestions on a way to monitor the battery temperature over time to confirm/deny my "feeling"?

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[CyberGus]

I lose almost 10% per day due to Sentry mode. This is disabled below 20% SoC, and now it’s losing almost nothing; I’ve been holding steady at 13% since I got home, I’ll see what it is in the morning.

When in standby, the 48v battery provides power, and the HV pack is activated only to keep the MV battery topped up. I’m guessing that is what’s happening every 13 minutes, but that doesn’t explain where the power is going.

Even a phone will detail its energy budget, but Teslas will not AFAIK. I’d recommend a Service ticket, but others have reported mixed results from doing so.

 

[Woodrick]

I've seen other people discuss phantom drain on their CTs, but I haven't seen any discussion with specifics about what is normal and what isn't. Back in the day I'd read about people having a 2% drop per day and them being upset about it. I'm seeing more like a 10% per day drain.

I left my CT for just under 2 weeks in an underground garage with sentry turned off, no wifi or cellular coverage, and I wasn't in town to accidentally have the car see me as nearby. I came back and the car went from 80% SOC to dead zero. Tesla had to send out a tow truck to give me a jump start (which is funny since I gave away my 12v jumper when I got the CT, even though that would have saved me the 12v jump I got). Needed the jump in order to unlock the charge port to plug it back in to my L2 charger (even with the flap open, the CT wont accept a charger being plugged in).

*Since* then, I've added the truck to Tessie. Even today on 2024.8.12, I'm seeing 10kwatts of power over 18 hours of being idle. Or a few days ago, while camping, I had 30kwatts consumed over 48 hours of it being parked (though that's not a great example as I was frequently around the car).

More specifically, while camping outside the truck, even with my app closed to prevent it from seeing me nearby, I'd hear the high voltage system click off every 13 minutes. Very specifically 13 minutes. Same sound you'd hear when you plug it into a charger and the high voltage system switches from 800 volts to 400 volts. Then ~30 seconds later (I didn't time it), you'd hear the two clicks of it getting enabled again. What I think is: the truck is going into the proper idle state, and then it's being woken up for some reason.

I don't have a good way to confirm this, but I have a feeling that the car is keeping the battery pack warm for some reason. It's somewhat just a guess with a few other signs that lead me to that feeling, but very much nothing formal. So, are other people experiencing the same? And any suggestions on a way to monitor the battery temperature over time to confirm/deny my "feeling"?

The underground garage may have been part of the problem. If the vehicle doesn't have cellular coverage, then "checking in" takes a lot more power.

The first thing to do is as @espresso-drumbeat suggest, look at the Energy pages.

The Cybertruck is new, it will take some time for Tesla to fine-tune the energy consumption.

 

[edh]

The underground garage may have been part of the problem. If the vehicle doesn't have cellular coverage, then "checking in" takes a lot more power.

Yea, I think this is a part of the problem - it's aggressively trying to find a signal just running in a loop.

If you're still seeing this when it is in the open, create a service request (also try a hard reboot first - this has helped me in the past on other, non-CT teslas).

 

[Lasttoy]

This seems to be alot for new car. Tesla must have a lot of stuff running in the background we haven't heard about. The only way to force the issue is everybody get service ticket.
I leave my car plugged in at night. But if I was not home that would cause a big problem.

 

[CyberGus]

I lose almost 10% per day due to Sentry mode. This is disabled below 20% SoC, and now it’s losing almost nothing; I’ve been holding steady at 13% since I got home, I’ll see what it is in the morning.

Went from 13% last night to 12% this morning, now at 11% when I arrived at work.

If not for Sentry mode, I could charge once a month lol

 

[CyberGus]

Look in the Energy monitor

Vehicle Standby : 10%
Sentry Mode: 20%
Browsing CTOC: 42%

 

[CyberGus]

FYI, there are plenty of "phantom drain" threads over on TMC, such as this current one:

https://teslamotorsclub.com/tmc/threads/non-random-battery-drain.322816/page-2#post-8220973

In this post, the user has postulated that the computer continues to "navigate" in standby if you park before reaching your GPS destination. I've disabled the Automatic Navigation for work/home so this would not affect me.

 

[ColonelZ]

For me its always sentry mode. Can drain like 15% over the course of a few days parked in a garage.

 

[Fleetwood75]

Good to know! I'm about to go on a 10 day vacation but I'll be leaving the truck at home so I guess I'll just leave it plugged in and remotely turn on the charger every few days.

 

[Woodrick]

Good to know! I'm about to go on a 10 day vacation but I'll be leaving the truck at home so I guess I'll just leave it plugged in and remotely turn on the charger every few days.

Why turn the charger off and on, just leave it plugged in.


From the manual:


Storage
If you leave Cybertruck parked for an extended period of time, plug the vehicle into a charger to prevent normal range loss and to keep the Battery at an optimal temperature. Your vehicle is safe to stay plugged in for any length of time.
When not in use, Cybertruck enters a sleep mode to conserve energy. Reduce the number of times you check your vehicle’s status on the mobile app, as this automatically wakes up your vehicle and starts normal energy consumption.

 

[Fleetwood75]

Why turn the charger off and on, just leave it plugged in.


From the manual:


Storage
If you leave Cybertruck parked for an extended period of time, plug the vehicle into a charger to prevent normal range loss and to keep the Battery at an optimal temperature. Your vehicle is safe to stay plugged in for any length of time.
When not in use, Cybertruck enters a sleep mode to conserve energy. Reduce the number of times you check your vehicle’s status on the mobile app, as this automatically wakes up your vehicle and starts normal energy consumption.

I guess I've never left my Model X plugged in for more than 24 hours. I currently have it schedule to begin charging at 9:00pm every night. If I plug in the truck will it just start topping itself off at 9:00pm every night? I guess so huh?

 

[BChiesa]

I guess I've never left my Model X plugged in for more than 24 hours. I currently have it schedule to begin charging at 9:00pm every night. If I plug in the truck will it just start topping itself off at 9:00pm every night? I guess so huh?

Pretty sure if you leave it plugged in, once it is at a full charge it pulls any additional power needs direct from the house. So it’s not constantly charging the battery.

 

[Fleetwood75]

Pretty sure if you leave it plugged in, once it is at a full charge it pulls any additional power needs direct from the house. So it’s not constantly charging the battery.

I don't think so because in the Model X it'll start charging at 9:00pm, finish (90% SoC) in the middle of the night (1:00am-ish) but i have Sentry mode turned on, and when I wake up the car is still plugged in but it's already down to like 88% SoC. Unless that 2% loss is due to temperature, but it's not cold here

 

[Woodrick]

I guess I've never left my Model X plugged in for more than 24 hours. I currently have it schedule to begin charging at 9:00pm every night. If I plug in the truck will it just start topping itself off at 9:00pm every night? I guess so huh?

If it needs to, that may be what it does. I'm not sure if anyone that has monitored it has monitored it with scheduled charging enabled.
But generally, it'll let the battery drop a few percent and then turn on for a little bit. Not a large amount, even if it does it during prime time.

I don't see it now, but the manuals used to include a phrase similar to "a plugged in car is a happy car"

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