Non random battery drain

[albanick]

I am the recently new owner of a 4 year old M3P and have noticed a very consistent battery drain issue. I've been reading threads on here for weeks and still can't figure this one out.

Every Wednesday, my battery 'loses' 4% while parked (not plugged in) at my work.

I downloaded teslafi to see if it gave me any more insight and all I can see is that I lose 4% while parked and the vehicle is sleeping.
Sentry mode is disabled and I don't have the self summon.
I raised a service ticket with Tesla and they said there is nothing abnormal in the log and it must just be the battery (bms) recalculating the actual available charge.
Bur every Wednesday (3 in a row) and always 4%. This surely can't be right.

Does anyone else have similar experience and importantly, has anyone found a fix (or at least the cause)?

Appreciate any help you can give.

 

[CyberGus]

 

[GtiMart]

With the information we have and what Tesla provided, we don't even know if it's a drain. They are in fact suggesting that it's not a drain, it's a readjustment of the displayed remaining energy. e.g. the car thinks there's 54% left initially and it ends up thinking 50% later. The actual "amount of energy" stored in the battery might not have changed at all.
What's clear is that measuring and displaying the total energy in the pack is an approximation, not an exact science. Maybe it could be exact in controlled conditions with additional hardware but not in the car as it is. The car also tries to account for things like temperature where a cold battery would produce less energy than a warm one, for the same quantity of energy stored in it, which further confuses the analysis. The display in my car can go down by as much as 7% in -20C weather overnight compared to when warm before I park it. No drain, just an adjustment of estimated available energy.
We know that there are variations in BMS and that some people can "help it" go higher by leaving the car at low SOCs sometimes, high SOCs other times etc. There are plenty of threads here. I've personally gotten my max range to go up by doing this. It's just an estimate, it has not changed the actual capacity of my battery, just the displayed (estimated) number.
The only thing that I find weird here is that it's only one day in the week. Is there any other variable in play that you are not accounting for? A different routine? time of day? charging regimen? do you park in another location on those days? etc?

 

[albanick]

With the information we have and what Tesla provided, we don't even know if it's a drain. They are in fact suggesting that it's not a drain, it's a readjustment of the displayed remaining energy. e.g. the car thinks there's 54% left initially and it ends up thinking 50% later. The actual "amount of energy" stored in the battery might not have changed at all.
What's clear is that measuring and displaying the total energy in the pack is an approximation, not an exact science. Maybe it could be exact in controlled conditions with additional hardware but not in the car as it is. The car also tries to account for things like temperature where a cold battery would produce less energy than a warm one, for the same quantity of energy stored in it, which further confuses the analysis. The display in my car can go down by as much as 7% in -20C weather overnight compared to when warm before I park it. No drain, just an adjustment of estimated available energy.
We know that there are variations in BMS and that some people can "help it" go higher by leaving the car at low SOCs sometimes, high SOCs other times etc. There are plenty of threads here. I've personally gotten my max range to go up by doing this. It's just an estimate, it has not changed the actual capacity of my battery, just the displayed (estimated) number.
The only thing that I find weird here is that it's only one day in the week. Is there any other variable in play that you are not accounting for? A different routine? time of day? charging regimen? do you park in another location on those days? etc?

Thanks for the reply Gtimart.

Yes, it's the consistency of the day of the week that is puzzling me. I understand the point that a battery is not a fixed amount of energy and so will vary with climactic conditions, but it shouldn't vary with the day of the week!

My routine is pretty fixed. Charge to 80% on a Monday, short journeys to and from work Monday to Friday, move the kids about at the weekend. Repeat.
Journeys are regular in terms of time. Parking location is the same all the time and the temperatures have been pretty consistent over the last few weeks. It's not like Wednesday has always been colder or hotter than the other days of the week.
Screenshot from Teslafi included in case it tells anyone anything that sheds more light.

 

[ewoodrick]

I am the recently new owner of a 4 year old M3P and have noticed a very consistent battery drain issue. I've been reading threads on here for weeks and still can't figure this one out.

Every Wednesday, my battery 'loses' 4% while parked (not plugged in) at my work.

I downloaded teslafi to see if it gave me any more insight and all I can see is that I lose 4% while parked and the vehicle is sleeping.
Sentry mode is disabled and I don't have the self summon.
I raised a service ticket with Tesla and they said there is nothing abnormal in the log and it must just be the battery (bms) recalculating the actual available charge.
Bur every Wednesday (3 in a row) and always 4%. This surely can't be right.

Does anyone else have similar experience and importantly, has anyone found a fix (or at least the cause)?

Appreciate any help you can give.

Does the car connect to Wi-Fi while at work?

What app are you using to collect the information? The app itself could be the culprit.

Have you looked at the Energy pages to see what they say?

Is Sentry OFF or OFF at work or home?

 

[albanick]

Does the car connect to Wi-Fi while at work?

What app are you using to collect the information? The app itself could be the culprit.

Have you looked at the Energy pages to see what they say?

Is Sentry OFF or OFF at work or home?

Thanks for the thoughts ewoodrick.

No WiFi connection at work but I do have premium connectivity subscription, so I guess the car can connect and send data if it wants?

I did only have the official tesla app, but after it happened 2 weeks in a row I registered to Teslafi to try to get more visibility of the issue. It does not seem to have made things better or worse.

The energy app in the car just says it is standby usage (with the annoying message alongside saying to leave the car plugged in when not in use)
I'm not sure whether it is possible to dig any deeper in the energy app (this is why I ended up registering for Teslafi)

Sentry mode is off.

I should have said in the original post that my wife also has a model Y and has done for a year and I have never noticed a similar issue with hers, so it's not just newbie misunderstanding of batteries.

 

[ewoodrick]

Thanks for the thoughts ewoodrick.

No WiFi connection at work but I do have premium connectivity subscription, so I guess the car can connect and send data if it wants?

I did only have the official tesla app, but after it happened 2 weeks in a row I registered to Teslafi to try to get more visibility of the issue. It does not seem to have made things better or worse.

The energy app in the car just says it is standby usage (with the annoying message alongside saying to leave the car plugged in when not in use)
I'm not sure whether it is possible to dig any deeper in the energy app (this is why I ended up registering for Teslafi)

Sentry mode is off.

I should have said in the original post that my wife also has a model Y and has done for a year and I have never noticed a similar issue with hers, so it's not just newbie misunderstanding of batteries.

If it is showing standby usage, that's where I'd look. If I am not mistaken, there is a standby setting under summon.

Also, do you happen to work in a different location in office during the week? Could the car be seeing your phone?

 

[fholbert]

I don't understand the one day a week discharge.

Have you tried to charge to 100% so the charge % recalibrates?

 

[albanick]

I don't understand the one day a week discharge.

Have you tried to charge to 100% so the charge % recalibrates?

No not charged to 100% since I bought the car so I'll give that a go and see if it does anything.

 

[albanick]

If it is showing standby usage, that's where I'd look. If I am not mistaken, there is a standby setting under summon.

Also, do you happen to work in a different location in office during the week? Could the car be seeing your phone?

How do I look at the standby usage further to see what was actually using the battery? This is what I had hoped Teslafi would give me.

My car is 2019, so no summon mode and therefore no options regarding standby mode (that I can find)

 

[ewoodrick]

How do I look at the standby usage further to see what was actually using the battery? This is what I had hoped Teslafi would give me.

My car is 2019, so no summon mode and therefore no options regarding standby mode (that I can find)

It's on the Energy page. Hit the center button and you should see it.

 

[ewoodrick]

There seems to be a few threads talking about this right now. I'd basically suggest just waiting until the next major release of software before getting too worried about it.

 

[GoergeJetson]

I am the recently new owner of a 4 year old M3P and have noticed a very consistent battery drain issue. I've been reading threads on here for weeks and still can't figure this one out.

Every Wednesday, my battery 'loses' 4% while parked (not plugged in) at my work.

I downloaded teslafi to see if it gave me any more insight and all I can see is that I lose 4% while parked and the vehicle is sleeping.
Sentry mode is disabled and I don't have the self summon.
I raised a service ticket with Tesla and they said there is nothing abnormal in the log and it must just be the battery (bms) recalculating the actual available charge.
Bur every Wednesday (3 in a row) and always 4%. This surely can't be right.

Does anyone else have similar experience and importantly, has anyone found a fix (or at least the cause)?

Appreciate any help you can give.

I've been experiencing a similar issue for the past several months. No drain at all when I'm parked at home, even over a 24 hour period. Each day when I go to work, I will see a 5%-6% "stand by" drain when parked in the parking lot. However, over the past 2 months, I have had at least two times where there was no battery drain. I do not have Sentry Mode on or cabin overheat protection. I have no aftermarket parts on the car, no changes electrically. As far as I can tell, the car is somehow using energy while parked at work, but not at home. The only difference is I don't have the car lock while at home, it does lock when I walk away from it at work. There is no wifi in the area where I park. I do park next to other cars but I've tried parking in different places in the parking lot with the same result. I have only the Tesla app on my phone, even if I close the app, I see the same drain when I come back to my car. I also have tried turning off (pausing) the audio system and turned off the climate HVAC.

Something else that's strange, I go out to lunch on Mondays, when I get in the car at noon the car has already lost 5% or more in 4 hours (again Sentry mode was not on at work), I drive it approximately 15 miles round trip to lunch, return back to the same parking lot, then the remainder of the afternoon, there is no further battery drain. It's just the oddest thing. I've run out of things to try, so I thought I'd post here.

I've tried turning on Sentry mode and I see an even higher drain of up to 9% or so, so I don't use it, the car is parked in a secure lot. It only takes about 10% for me to drive 27 miles to work so losing more than half of that while parked is bothering me because it's only within the several months I've been having this issue so I do believe it's software related. I've gotten updates, rebooted, etc. Still no change.

Last week I even reported the issue to Tesla and all I got was the canned response on how your vehicle will use energy while parked for Sentry mode and to keep the car plugged in.

 

[TXJarhead99]

I consistently lose 5% per day when parked at work. I consistently gain that 5% back between the time I arrive home and scheduled charging starts at 11 P.M.

I stopped worrying about it months ago.

 

[KenC]

I've been experiencing a similar issue for the past several months. No drain at all when I'm parked at home, even over a 24 hour period. Each day when I go to work, I will see a 5%-6% "stand by" drain when parked in the parking lot. However, over the past 2 months, I have had at least two times where there was no battery drain. I do not have Sentry Mode on or cabin overheat protection. I have no aftermarket parts on the car, no changes electrically. As far as I can tell, the car is somehow using energy while parked at work, but not at home. The only difference is I don't have the car lock while at home, it does lock when I walk away from it at work. There is no wifi in the area where I park. I do park next to other cars but I've tried parking in different places in the parking lot with the same result. I have only the Tesla app on my phone, even if I close the app, I see the same drain when I come back to my car. I also have tried turning off (pausing) the audio system and turned off the climate HVAC.

Something else that's strange, I go out to lunch on Mondays, when I get in the car at noon the car has already lost 5% or more in 4 hours (again Sentry mode was not on at work), I drive it approximately 15 miles round trip to lunch, return back to the same parking lot, then the remainder of the afternoon, there is no further battery drain. It's just the oddest thing. I've run out of things to try, so I thought I'd post here.

I've tried turning on Sentry mode and I see an even higher drain of up to 9% or so, so I don't use it, the car is parked in a secure lot. It only takes about 10% for me to drive 27 miles to work so losing more than half of that while parked is bothering me because it's only within the several months I've been having this issue so I do believe it's software related. I've gotten updates, rebooted, etc. Still no change.

Last week I even reported the issue to Tesla and all I got was the canned response on how your vehicle will use energy while parked for Sentry mode and to keep the car plugged in.

As I mentioned to others, I believe, and I may be wrong, that the BMS recalculates your range whenever you "start" a trip. So, if your ambient temps have changed from home to work, then you'll get a different range calculation when you re-start your car.

In Winter, you often get these questions, because people will notice their car has lost range from when they parked, and that's because it's colder where they parked than at home. On warmer days, they won't see a range drop, so you rarely get these questions in warmer months. No one complains about the odd BMS behavior when range goes up!

Below is a screenshot of my Energy Consumption screen during a power outage. Each day was a significantly different temperature, so Day 1 was warmer than Day Zero, so the BMS showed a little more SOC. Then Day 2 was much colder than Day 1, so that day, the SOC dropped about 4%. And Day 3 was also colder, so it dropped as well. As you can see, it goes both up and down.

The key is relative temperature change that the BMS sees. So, if the BMS sees a cold day, it could still go up, if it was even colder the day before. Relative change. That relative change is why people find the difference seemingly random, and not correlated with temps. It's not correlated with temps, but the change in temps.

In your example, you mentioned a couple days where the BMS didn't show lower range at work. Were those days warm at work? And when you have lunch, and there's no further drain, afterward, it's because the car is seeing approx. the same ambient temps before and after lunch.

 

[PianoAl]

Valet parking on Wednesday?

 

[GoergeJetson]

For me this is not a BMS issue and I'm in FL, it's not a cold weather issue, I do not get the 5% back later in the charge/discharge cycle, and depending on what I do when I arrive at work, the drain will change. For example, earlier this week, I parked the car when I got to work, then after 2 hours I went out to the car, found 4.8% loss, drove the car around the parking lot, then 8 hours later, came back to the car and there was no further decrease in percentage. So I can stop the energy loss just by moving the car after it's parked for a while at work.

So yesterday, prior to arriving at work, I cancelled my destination in the navigation system, parked the car, and when I came out to the car I only lost 2.5%, half of what the car has been losing after only a few hours, and it was a 90 deg day.

I've even experienced near 0% loss on random warm or cool days. If I can affect the amount of loss each day, I don't think it's the BMS giving a false remaining percentage, then correcting after the car sits. I believe there is something not shutting down, the car is still awake, even though it's parked. 5%-6% is nearly 4 kW, which is a pretty significant amount of energy. In the past, I would use Sentry Mode and it would use 6% of energy each day, now I'm not using Sentry mode and the car is using a similar amount of energy.

Recently, I turned Sentry mode on for the day and I lost around 7% while the car was parked, just slightly more than not using Sentry mode, sure seems like there is a software bug that was introduced about a year ago.

I've checked with other owners online, there are some people that are also experiencing the same problem, seems to be mostly 2019 and 2020 models. I don't have FSD or EAP, there is no summon mode so I can't change anything with regards to vehicle standby, but it's almost like the car is in a standby mode waiting for Summon to be activated, which would use more energy since the car would not be fully in sleep mode like it is at home.

 

[ewoodrick]

For me this is not a BMS issue and I'm in FL, it's not a cold weather issue, I do not get the 5% back later in the charge/discharge cycle, and depending on what I do when I arrive at work, the drain will change. For example, earlier this week, I parked the car when I got to work, then after 2 hours I went out to the car, found 4.8% loss, drove the car around the parking lot, then 8 hours later, came back to the car and there was no further decrease in percentage. So I can stop the energy loss just by moving the car after it's parked for a while at work.

So yesterday, prior to arriving at work, I cancelled my destination in the navigation system, parked the car, and when I came out to the car I only lost 2.5%, half of what the car has been losing after only a few hours, and it was a 90 deg day.

I've even experienced near 0% loss on random warm or cool days. If I can affect the amount of loss each day, I don't think it's the BMS giving a false remaining percentage, then correcting after the car sits. I believe there is something not shutting down, the car is still awake, even though it's parked. 5%-6% is nearly 4 kW, which is a pretty significant amount of energy. In the past, I would use Sentry Mode and it would use 6% of energy each day, now I'm not using Sentry mode and the car is using a similar amount of energy.

Recently, I turned Sentry mode on for the day and I lost around 7% while the car was parked, just slightly more than not using Sentry mode, sure seems like there is a software bug that was introduced about a year ago.

I've checked with other owners online, there are some people that are also experiencing the same problem, seems to be mostly 2019 and 2020 models. I don't have FSD or EAP, there is no summon mode so I can't change anything with regards to vehicle standby, but it's almost like the car is in a standby mode waiting for Summon to be activated, which would use more energy since the car would not be fully in sleep mode like it is at home.

Is the Cabin Overheat Protection enabled?
Do you use any third party apps to monitor your car?
Does it continue to drop over multiple days?

 

[GoergeJetson]

Is the Cabin Overheat Protection enabled? Nope.
Do you use any third party apps to monitor your car? Nope.
Does it continue to drop over multiple days? I don't leave the car at work multiple days, but at home it doesn't lose energy over one day or multiple days, not like at work.

 

[sjkjs]

I have the same issue. It ONLY happens between 60-65% and I lose around 5% or so while the car is asleep. It doesn't seem to be affected by temperature or by firmware updates.

If I park the car with 66% then come back later, it will still be on 66% (no drain). If I park on 65%, when I get back later it will have dropped to around 60%. It's like the BMS thinks the entire range between 60-65% doesn't actually exist, but weirdly if I start on e.g. 70% and go for a longer drive which ends on say 50%, the battery level steadily goes down as you would expect it to throughout the drive. There are no sudden drops or anything else unexpected.

I regularly let the car sleep at all different charge levels. I've charged it to 100% (and also topped off until charging stopped).

I'm quite confident that it's not actual "drain", it's BMS inaccuracy, but it never seems to adjust to correct the issue.