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What is acceptable ‘idle’ charge loss?

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Mrklaw

Active Member
Mar 5, 2020
2,623
1,734
Berkshire
Only just got the car. On Friday we went for a drive, came back and charged the car up to 80% around late afternoon. This morning just checked the app (first time opening it since Friday) and it’s showing 73%. No sentry mode on. Seems like a lot of drop for 1.5 days?

What’s normal to expect and what factors can affect it? Eg if it’s always in range of my phone will that be an issue, that kind of thing.
 
Are you allowing the car to sleep? Have you installed any other apps that may be keeping the car awake?

A 7% drop does seem like a lot. However, there may be an element of battery cooling, which may lower the available capacity of the battery.
 
No apps except Tesla’s installed. Not doing anything I’m aware of to prevent sleeping, was not plugged in.

hearinf some stories about Bluetooth range and only living in a small UK house with the car on the drive close by - could being in range of my phone nee waking it up even if I’m not using the app at all?
 
up to 1% a day (LR/P) is normal for a a sleeping car. so this does seem high
if you parked when warm though and now are checking it on a cold morning that could have an affect. you need to check over a longer period to build up a pattern of behaviour.
Also check if you have cabin overheat protection on. We have had some sunny weather so that could kick in even in March
do a double button reboot
Don't keep checking the app during your test period that will wake it.
if you have ever logged into any other app or service change you PW that will invalidate any 3rd party access.
being in range of the phone is not an issue so long as you don't open the app
 
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I wouldn't be concerned. It does sound quite a lot but there are several plausible explanations that may show it as being normal.

One of the bigger factors is reading too much into the % displayed in the car or the app. Even though the actual state of battery charge can remain largely fixed, the displayed % can be adjusted up and down due to a variety of factors.

You mention that you charged late afternoon after a drive. The battery was likely to have been in a state whereby the displayed % closely resembled the true state of the battery. So charging to 80% would likely give you close to 80% usable battery when the battery was warm. However, as the battery cooled, this 80% was really less than this usable, hence seeing less than 80% indicated.

If you charged up in ideal conditions but viewed in sub optimal conditions, battery cold etc, then you could well have seen a big drop in %.

80% charge, nice warm day, immediately after a drive then viewing on a cold morning before warming the car up, 5% or more is easily explainable (seen in likes of TeslaFi but in normal app can be partially confirmed by temporarily sliding the charge % to 100% and seeing if maximum allowed is 100% or less).

The remaining losses could also have easily explainable reasons, such as frequent checking of app (every time you open the app it wakes the car), only seeing whole integer % values, cabin overheat protection, normal car losses etc etc.
 
Only just got the car. On Friday we went for a drive, came back and charged the car up to 80% around late afternoon. This morning just checked the app (first time opening it since Friday) and it’s showing 73%. No sentry mode on. Seems like a lot of drop for 1.5 days?

What’s normal to expect and what factors can affect it? Eg if it’s always in range of my phone will that be an issue, that kind of thing.

In my experience it can actually vary quite a bit. Which car do you have? (It's helpful to put that in your sig so that you don't have to quote your model overtime you make a post.) Yes, on the face of it that's a larger drop than usual but not unknown. If the car has been kept awake there will be higher losses ... sometimes you may be responsible for that by checking the app, which then wakes the car ... it will also be the case if you leave Sentry Mode active. Another factor is temperature because the display shows the percentage that is actually available ... as the battery warms you can regain the "loss". Some software updates seem to trigger more active patterns of car wakefulness for a while. Other times the reason for higher losses are not immediately apparent but from posts on the forum it is very rarely due to a fault. It's generally one of those issues that is best not dwelled upon ... you don't want to develop "range anxiety" when the car isn't even in use!
 
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As others have said there are lots of different factors here but I find that temperature makes the biggest difference and this will settle down as the weather warms up. If it continues to happen then I suggest you check that you haven't accidentally set it to precondition the battery I managed to do this a while back (fat fingers etc.) and it really drained the Battery I removed this setting and issue resolved.
 
Hadn’t opened the app between Friday afternoon and this morning. Overheat protection shouldn’t have been a thing as it isn’t that warm here. Cold morning could be a factor I guess.

I’ll keep an eye on it
If it’s sunny and the car is parked in the sun the car internal temperature goes up surprisingly high regardless of exterior temperature (I guess glass roof is probably responsible for this) - I’ve had 26 degrees inside the car when it was 2 degrees air temperature outside! Set cabin overheat to fan only or off.

Also has your car tried to download an update?
 
I genuinely wouldn’t worry. Think back to your ICE days when you looked at the fuel gauge to see if there was enough to get you there and back and treat your Tesla the same.
shrt journeys with heater on will make the range dreadful. I’ve just done three 2 mile journeys; 2 with heat and 1 without. Used 25 miles of range. A 40 mile journey will be much closer to reality.
 
There's a thread here that details similar experiences.


I had circa 4% batter loss overnight and had checked absolutely everything noted above. The problem went away after one of the many software updates from Tesla. To see if you really have got an issue, you need to test it over a longer period - was easier over lockdown when we were travelling a lot less. If you are able to not use the car over a few days you will get a better idea of the true loss.
 
Installed teslafi - just left on defaults - based on below (left overnight not used the app or anything) it was pretty much awake the entire night and only slept for 1 minute at a time?

43ABF7BC-3B2A-4AB6-9344-0961C927D6AE.jpeg


Edit : just opens the Tesla app for the first time this morning and it says 76% (was 82% when I stopped the charger around 6pm yesterday) and haven’t touched since
 
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Be careful with apps, they can keep the car awake themselves. I would pressing the default setup of TeslaFi doesn’t do that though.

Do you have Summon Standby enabled? That will keep the car awake. It’ll also stay awake if it’s unlocked, or Sentry is active, or if Cabin Overheat Protection is enabled and currently active, and probably other things besides.

It may even be awake disproportionately at the moment because it’s new and Tesla are gathering info from it? I dunno.
 
If you click on the zzz or the P icon, it will open the logs for that period. Final column may well have some info about what may be causing the car to wake and fields around the rows when the car woke may also shed some light - you can change the headers to show different fields.

What you would expect to happen is (for us, but your settings may vary) 20 minutes after car had stopped being used, you should see TeslaFi stopping polling - this will be in the logs above. TeslaFi will then stop polling ('trying to sleep') for in our case 10 minutes, after which it checks the car state and either declares the car asleep, or that it failed to go to sleep. If you see the latter, all likelihood is that some activity/state of the car is keeping it awake. This is not unusual, especially after a drive or a very hot/cold spell (thermal management), but if not at the xtremes of temperature, if car refuses to sleep after 2-3 hours, something odd is going on.

I think your scenario definitely needs further investigation.
 
Be careful with apps, they can keep the car awake themselves. I would pressing the default setup of TeslaFi doesn’t do that though.

Do you have Summon Standby enabled? That will keep the car awake. It’ll also stay awake if it’s unlocked, or Sentry is active, or if Cabin Overheat Protection is enabled and currently active, and probably other things besides.

It may even be awake disproportionately at the moment because it’s new and Tesla are gathering info from it? I dunno.

right but I installed teslafi because of the car seeming to use too much energy and overall impressions was teslafi behaves itself. I know it adds another complexity to working out whats going on but it does look like the car goes to sleep, immediately wakes up, then repeats every 40-45 mins

here is the latest P entry followed by the latest Zzz entry

C7C686CC-9EE4-47A6-9721-E879B3D79D30.jpeg


3BD75A7A-19E1-4AFB-99E1-35633873049D.jpeg
 

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I know you have no other apps running, but always worth resetting your Tesla password just to rule out anything else talking to the car. It's the first thing Tesla will ask you to do if you report this as an issue. There's a bit of me that thinks the cars don't properly disconnect from the servers and a password reset will make sure they are no longer connected.
 
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In my experience it can actually vary quite a bit. Which car do you have? (It's helpful to put that in your sig so that you don't have to quote your model overtime you make a post.) Yes, on the face of it that's a larger drop than usual but not unknown. If the car has been kept awake there will be higher losses ... sometimes you may be responsible for that by checking the app, which then wakes the car ... it will also be the case if you leave Sentry Mode active. Another factor is temperature because the display shows the percentage that is actually available ... as the battery warms you can regain the "loss". Some software updates seem to trigger more active patterns of car wakefulness for a while. Other times the reason for higher losses are not immediately apparent but from posts on the forum it is very rarely due to a fault. It's generally one of those issues that is best not dwelled upon ... you don't want to develop "range anxiety" when the car isn't even in use!

I totally agree, this is the answer. It can vary quite a bit.

I can lose 1 mile a day for 4 days or 20 miles in one night. Car does a lot stuff. Might be downloading maps, updates or uploading data.

Conditions you monitor at for each point can make it read differently. Like it’s hot at one measurementand cool at another.

It’s just measuring a voltage.

Car might have updated calibration after the last charge.

Just watch it over time. On average it should be low.

Watch out for FOB left inside or to close to the car can parent deep sleep. And a half dozen other things. Sentry, Standby Summon, cabin protection etc.

First 12 hours after parking can vary a lot more than subsequent intervals.
 
Those screenshots seem to suggest that as soon as it actually falls asleep it just wakes up again straight away.

~15 minutes is typical for “falling asleep” to “asleep”, except after a software update or a reasonable length drive.
 
Only just got the car. On Friday we went for a drive, came back and charged the car up to 80% around late afternoon. This morning just checked the app (first time opening it since Friday) and it’s showing 73%. No sentry mode on. Seems like a lot of drop for 1.5 days?

What’s normal to expect and what factors can affect it? Eg if it’s always in range of my phone will that be an issue, that kind of thing.
Just got my car back from the sc after having a similar overnight drop. I bought the car as a CPO and have no third party equipment connected such as dashcams or trackers. However, they did find a third party mounted device ( likely to be the leftover from previous owners dashcam). This device may not have consumed much power but obviously enough to have the car walking up and having to maintenance charge the 12v battery. Now, after that the device is removed, my car is no longer having the nightmare phantom drain anymore. So, all of you that may see phantom drain that is over and above the normal, try to disconnect any installed dashcam / trackers to see if you may have a similar issue. Also, be aware that Tesla will charge for labor if the drain is found to be caused by a third party device. As I didn't install the device, I didn't have to pay for the troubleshooting ( but at the same time, they will remove the this party device and keep it which was fine for me as it has been draining 100+ kWh since I bought the car last year).
 
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