Idle Battery Drain

[MMBTUS]

I know this topic gets discussed with some frequency, especially on certain updates, but in the past week or two I've notice the issue become more serious with my car (vin 12xxx, on software 44.2). Basically I'm losing about 1 mile per hour of idle sitting. I've got screenshots showing the car unmoved 6 hours apart with 5-8 miles lost in the time period. Overnight, I come back to my car with 10 less miles.

I spoke with the local Tesla service center (Dedham, MA), and they're going to look at it when I take it in for an appt I already have for 12/20. I'm just wondering if anyone else is having this severe of a rate of drain? Pretty frustrating, especially in the winter when energy usage is already up.

Learn about idle versus sleep modes. Subscribe to TeslaFi to track your car’s idle and sleep periods. You can also use TeslaFi to “force” your car to sleep after so many minutes. Why important? Losses during sleep mode are practically zero, regardless of duration. Losses during idle mode can be prodigious. Putting your car to sleep is very effective at minimizing drain. Are you idling more than sleeping?

 

[lolder]

1 mi/hr of battery loss is huge. My vehicle has been in the service shop since the 29th and it loss 9% over a week that's about 4 miles/day. Of course i'm in a mild climate right now (40-70 F)

AFAIK, there are a few big killers of range:

• Checking your vehicle status regularly which prevents it from entering "sleep". This is the biggest cause of drain. The car will stay idle for half an hour to a few hours drawing about 150-300 watts.
• Cabin Overheat Protection (I wonder if it does the same for low temperature)
• Smart Preconditioning
• Other climate related settings

If I don't do any of those, I'd be comfortable leaving it unplugged for a long time UNLESS a software bug is introduced. Bjorn noted a software bug in cold climate in V9 during one of his recent videos on an X which loss 35% in 3-4 days.

This whole LEAVE YOUR CAR at 80-100% charge is bogus IMO and Tesla needs to fix that ASAP. I've been driving EVs for 10 years, and I left my Volt with 30 miles of range OUTSIDE for 2 weeks and I came back to 30 miles of range. I also left it once in a garage for 3 weeks during an international trip still saw no appreciable range loss. This is while checking it remotely via the OnStar app.

I think Bjorn had trouble with his X charge port causing the drain.

 

[AlanSubie4Life]

Learn about idle versus sleep modes. Subscribe to TeslaFi to track your car’s idle and sleep periods. You can also use TeslaFi to “force” your car to sleep after so many minutes. Why important? Losses during sleep mode are practically zero, regardless of duration. Losses during idle mode can be prodigious. Putting your car to sleep is very effective at minimizing drain. Are you idling more than sleeping?

Agreed. Definitely the issue is idle mode. A third party app should not be necessary though!

After doing experiments last night:

Lost 51 miles of range in 53 hours?!

I left the car sleeping. It’s 60 degrees or warmer in the garage.

Checked my WiFi traffic this morning. Car woke up at around 5AM, and has been uploading tiny amounts of data. Battery has gone from 243 miles last night to 239 miles now due to what must be about 200+ watt drain for more than 4 hours. See attached. The WiFi traffic seems to be an excellent indicator of when the car is idle - plus I can see how useless the 4-5 hours in idle has been! (iOS widget actually seems to work too, it all correlates.). This looks like a somewhat more severe event than “normal”.

It is true that losses in sleep mode are very small.

Tesla, rather than a third party app, should just ensure the car is “idle” for very short periods (or not at all). That would solve 90% of the drain issue.

Pretty obvious this idle mode serves no useful purpose. It’s just hurting my electricity bill and putting LOTS of miles on my HV battery. Definitely hurting, not helping, the battery, though the effect is relatively small (increases miles on the battery by about 10%). I’ve put about 100 miles on my battery when sitting in the garage, and I’ve driven about 900 miles.

 

[AlanSubie4Life]

Today high was 9F. It was 4F when I got to Work and 5F when I left 11 hours later. I switched my gauge from Miles to battery percent as the miles are sort of meaning less since I’m getting at Best 400 W hours per mile. Anyway in those 11 hours I lost 5% battery. So that would be about 15 miles

That is high for “normal” idle mode drain, it is 0.05*75kWh/11hours = 340W average, compared to more normal 100-150W drain, so I assume a portion of this is battery conditioning. Assuming you did not prewarm car or gathered data before warming.

I would assume it actually went to sleep for a few hours after you got to work (could check manually using iOS widget or get historical data from a non invasive app). Then it woke up when it got cold, and was using something closer to 500W per hour or more.

However, it’s also possible it was just wasteful Tesla stuff and it was cranking data up to Tesla servers and otherwise wasting energy rather than battery warming. For that you’d have to be able to see the LTE traffic. Or have WiFi in the work parking lot you could log.

 

[MMBTUS]

Agreed. Definitely the issue is idle mode. A third party app should not be necessary though!

After doing experiments last night:

Lost 51 miles of range in 53 hours?!

I left the car sleeping. It’s 60 degrees or warmer in the garage.

Checked my WiFi traffic this morning. Car woke up at around 5AM, and has been uploading tiny amounts of data. Battery has gone from 243 miles last night to 239 miles now due to what must be about 200+ watt drain for more than 4 hours. See attached. The WiFi traffic seems to be an excellent indicator of when the car is idle - plus I can see how useless the 4-5 hours in idle has been! (iOS widget actually seems to work too, it all correlates.). This looks like a somewhat more severe event than “normal”.

It is true that losses in sleep mode are very small.

Tesla, rather than a third party app, should just ensure the car is “idle” for very short periods (or not at all). That would solve 90% of the drain issue.

Pretty obvious this idle mode serves no useful purpose. It’s just hurting my electricity bill and putting LOTS of miles on my HV battery. Definitely hurting, not helping, the battery, though the effect is relatively small (increases miles on the battery by about 10%). I’ve put about 100 miles on my battery when sitting in the garage, and I’ve driven about 900 miles.

View attachment 361182

I see some evidence that the 46.2 update has materially reduced phantom drain when idling. Anyone else notice?

 

[ConcordeSST]

Agreed. Definitely the issue is idle mode. A third party app should not be necessary though!

Tesla, rather than a third party app, should just ensure the car is “idle” for very short periods (or not at all). That would solve 90% of the drain issue.

View attachment 361182

I would look at TeslaFi more as a troubleshooting tool since you don't seem to want to use it on a daily basis (though for someone that seems to like data as much as your comments indicate, I genuinely think you'd be thrilled with it. I resisted for a while, and now I love it). You are correct that a third-party app should not be necessary to put the car to sleep, but if something is keeping the car from sleeping, then TelsaFi likely won't be able to put the car to sleep and will show you that in its raw data feed. I use it all the time now just to see if my car is asleep or not.

It has a 14 day trial, or 30 days if you ask someone here for a referral. That should be enough time to get a sense of what it can tell you about the car and the power draw in various modes. No obligation, no credit card needed.

Also, don't rely too much on Google WiFi for information on the car's wake/sleep cycles. I have it as well and I've seen it report phantom activity from my car during periods when my car isn't even at home.

 

[noicepls]

I see some evidence that the 46.2 update has materially reduced phantom drain when idling. Anyone else notice?

Ever since 42.2 and thru 46.2 updates with their so-called "cold weather improvements", I find the phantom drain has indeed lessened, but at the expense of more, and extremely frequent, sleep sessions. In effect, my Model 3 always seems to want to go into sleep mode at the slightest opportunity, which is very frustrating. For example: at a shopping trip where the car is parked any more than twenty minutes, it needs to be jolted out of sleep. The screen takes 40 seconds to boot up when I'm ready to depart already!! This is ridiculously impractical.

There should be a direct user setting to allow when the car should go into sleep mode instead of the current built-in auto one-setting-fits-all approach.

 

[Daniel in SD]

Ever since 42.2 and thru 46.2 updates with their so-called "cold weather improvements", I find the phantom drain has indeed lessened, but at the expense of more, and extremely frequent, sleep sessions. In effect, my Model 3 always seems to want to go into sleep mode at the slightest opportunity, which is very frustrating. For example: at a shopping trip where the car is parked any more than twenty minutes, it needs to be jolted out of sleep. The screen takes 40 seconds to boot up when I'm ready to depart already!! This is ridiculously impractical.

There should be a direct user setting to allow when the car should go into sleep mode instead of the current built-in auto one-setting-fits-all approach.

You can wake it from the app while walking back to your car. I think this may be the reason Elon founded Neurallink. In the future a brain-machine interface will be able know when you want to drive the car and wake it from sleep.

 

[AlanSubie4Life]

. The screen takes 40 seconds to boot up when I'm ready to depart already

Weird. Never seen that, even when I know the car was in sleep, due to the iOS app widget (doesn’t wake the car) & the contactors clicking on when I open the door, and WiFi traffic (and lack of quiet charge port clicking). Car starts right up. Another software issue I suppose. Sleep mode doesn’t seem to cause any delays when it is working properly.

 

[AlanSubie4Life]

Also, don't rely too much on Google WiFi for information on the car's wake/sleep cycles. I have it as well and I've seen it report phantom activity from my car during periods when my car isn't even at home.

Hmm. Haven’t noticed. As mentioned above, so far the traffic has correlated well with:

iOS widget status (does not wake the car)
Charge port lack of clicking
Contactor clunking (only happens when entering/exiting sleep)

Anyway I mostly just use it as an indicator and there are enough cross checks I think I’ll be able to tell when the data is bad.

 

[Dave EV]

For example: at a shopping trip where the car is parked any more than twenty minutes, it needs to be jolted out of sleep. The screen takes 40 seconds to boot up when I'm ready to depart already!! This is ridiculously impractical.

That's not the car sleeping, that's the screen crashing when you get into the car, which is a separate bug. The screen should always wake up instantly on the Model 3.

BTW - you can depart while the screen is still booting up, you just can't use any of the screen functions while it's doing so.

 

[AlanSubie4Life]

That's not the car sleeping, that's the screen crashing when you get into the car, which is a separate bug. The screen should always wake up instantly on the Model 3.

BTW - you can depart while the screen is still booting up, you just can't use any of the screen functions while it's doing so.

Yes, can confirm that. Screen will boot even before the contactors engage, I noticed this weekend. (I guess I am surprised by this...means that they must be using the 12V battery to power the screen for a period of time? Unless there are multiple contactor pairs for the HV battery and one is always connected? I have no circuit diagram to refer to. )

Anyway, I tried this weekend departing as quickly as possible, when I knew the car was in sleep mode before opening the car. There is a brief delay (systems still starting up) message if you go too fast (just a couple seconds from when you're in the car to when you put it in drive), but it's very short. Mostly the screen should turn on right away and you should be good to go in very reasonable period of time (certainly less than 5 seconds).
If @noicepls is having his system reboot spontaneously, frequently, @noicepls should take it to Tesla service to look at it! Or file a complaint through your Tesla account and maybe they'll be able to look at it remotely.

 

[noicepls]

If @noicepls is having his system reboot spontaneously, frequently, @noicepls should take it to Tesla service to look at it! Or file a complaint through your Tesla account and maybe they'll be able to look at it remotely.

Spoke with T service two weeks ago. Was told they'll check the logs and get back to me. So far, no word.
BTW, agreed it's possible to drive while the screen is booting up, but can't drive if you need navigation - there's no screen and no sound until it boots up.

 

[Daniel in SD]

Another big problem with the vampire drain that I didn't realize is that all that power is being cycled through the tiny 12V lead acid battery. It sounds like we will also have to replace our 12Vs every couple years like the Model S. At least it look pretty easy to access.

 

[AlanSubie4Life]

Another big problem with the vampire drain that I didn't realize is that all that power is being cycled through the tiny 12V lead acid battery. It sounds like we will also have to replace our 12Vs every couple years like the Model S. At least it look pretty easy to access.

Well, in idle mode, at least, the contactors are on, so that is coming from the HV mostly (presumably). That’s where the bigger draw is.
But yeah, I was wondering about that today. I know nothing about lead acid batteries, but clearly they are what are powering the screen and any other items when you first open the door before the “clunk”. Briefly. And the 10W (or less) draw in sleep mode...certainly it is from the 12V (??? - well not certain but I assume there aren’t other contactors to a secret HV battery)).
Is it ok to cycle lead acid batteries like this? Do they have a cycle limit if you don’t deep discharge them? I know there are AGM batteries and such...but really no idea.

I think in sleep mode we’re probably looking at a max of about 250Wh before it leaves sleep. And probably less since it pops out of sleep once a day or more. I’m not familiar with how the apps keep track of this stuff but presumably there is something in the API to read back how much was used in any particular sleep mode cycle - and that is what things like Tesla Fi report.

 

[gaoruijie]

1 mi/hr of battery loss is huge. My vehicle has been in the service shop since the 29th and it loss 9% over a week that's about 4 miles/day. Of course i'm in a mild climate right now (40-70 F)

AFAIK, there are a few big killers of range:

• Checking your vehicle status regularly which prevents it from entering "sleep". This is the biggest cause of drain. The car will stay idle for half an hour to a few hours drawing about 150-300 watts.
• Cabin Overheat Protection (I wonder if it does the same for low temperature)
• Smart Preconditioning
• Other climate related settings

If I don't do any of those, I'd be comfortable leaving it unplugged for a long time UNLESS a software bug is introduced. Bjorn noted a software bug in cold climate in V9 during one of his recent videos on an X which loss 35% in 3-4 days.

This whole LEAVE YOUR CAR at 80-100% charge is bogus IMO and Tesla needs to fix that ASAP. I've been driving EVs for 10 years, and I left my Volt with 30 miles of range OUTSIDE for 2 weeks and I came back to 30 miles of range. I also left it once in a garage for 3 weeks during an international trip still saw no appreciable range loss. This is while checking it remotely via the OnStar app.

how about your Teslafi's setting?