My 1 month old model 3 loses 4-5% battery parking overnight

[AlanSubie4Life]

It was not preconditioning at all.

So that is a little odd, and could be a bug, if you actually selected Supercharger from the destination list (no pin).

However, if the car thinks the battery will be warm enough, or your arrival SOC is too low to allow it, then preconditioning may be avoided. Effectively it is preconditioning - it just isn’t doing anything because it decided the pack is warm enough. It may decide it wants to warm even more when it gets there, still.

Anyway it all depends. In general if what it is doing makes sense, then it is fine. If it doesn’t make sense it is probably a bug.

Arriving at 20% it may have just decided that 210kW was good enough (if you arrive at 20% you are not trying to optimize travel time so you likely care less about preconditioning). Warming at the Supercharger is more energy efficient (less time for heat loss). Remember it costs you money to precondition (if no FUSC).

All depends on situation. And bugs can also exist.

 

[Edtreo]

In Kyle's latest video

he mentioned that the latest software update uses dynamic preconditioning. It is based on several factors to determine the temperature of the battery upon arrival at SC station. If your Tesla requires deep charging to reach your destination, preconditioning will not heat as much.

 

[AlphaGigaChad]

I lose about 1% overnight with sentry mode off and no preconditioning set for the next morning in my March 2022 Model 3 RWD, even in cold weather.

 

[AAKEE]

I lose about 1% overnight with sentry mode off and no preconditioning set for the next morning in my March 2022 Model 3 RWD, even in cold weather.

My car lost less than 2% in three weeks parked in my garage when I was in the states. (I regularly use low SOC and the self discharge is lower at lower SOC so that helps. Over 80% the self discharge is much higher. (Not that the self discharge is the main thing for loosing SOC during single nights, but mentioned as information)

But when the battery cools in cold WX the displayed number is shifted down (by purpose from Tesla). The BMS still have the same number as when the car was parked.
I did a few weeks ago with 55%, and after a couple of days with -15- -20C the battery was about -15C and the car did show 52% SOC, but the BMS did show 54.8% SOC.

 

[AlanSubie4Life]

My car lost less than 2% in three weeks parked in my garage when I was in the states.

Lower than I would expect (wonder whether new vehicles have lower drain than the older ones somehow).

Another possibility is that the BMS adjusted upwards before heading downwards. So rather than expected 20 (6%) miles you saw 6 or whatever. But only way to tell would be to check after parking for a while, before you leave.

Not sure if you ever have occasion to measure over a week or so (excluding initial transient). Hint hint. Lol.

Could be either. No idea if they have changed the hardware somehow to address the typical 200Wh/day loss. Or maybe I just haven’t measured recently and it is even lower than 200Wh/day for my car! Things are always changing.

 

[XPsionic]

I've parked my 2021 SR+ for up to 2 weeks at a time in a climate controlled garage (76f), only lose like 1-2% a week from the 55kw pack.

Before I bought the car I was a bit worried about phantom drain since my parking doesn't have dedicated charging, but now I don't even think about it at all when I leave town for a while. I don't check the app at all anymore, just leave it alone and it's always fine when I get back.

 

[AlanSubie4Life]

I've parked my 2021 SR+ for up to 2 weeks at a time in a climate controlled garage (76f), only lose like 1-2% a week from the 55kw pack.

Before I bought the car I was a bit worried about phantom drain since my parking doesn't have dedicated charging, but now I don't even think about it at all when I leave town for a while. I don't check the app at all anymore, just leave it alone and it's always fine when I get back.

I assume this is not plugged in? I’ve never paid attention or tested but not convinced behavior is identical with not plugged in vs. plugged in with charge limit set below current SOC.

Not sure exactly which pack you have. There is a SR+ LFP and SR+ NCA similar FPWN values but different typical values.

(Why is home charging only 32 amps on SR when supercharging is so much faster?)

Anyway 2% works out to something like 53.5kWh*0.955*0.02= 1kWh.

Which over two weeks would be 70Wh/day. Nice and low!

 

[XPsionic]

I assume this is not plugged in? I’ve never paid attention or tested but not convinced behavior is identical with not plugged in vs. plugged in with charge limit set below current SOC.

Not sure exactly which pack you have. There is a SR+ LFP and SR+ NCA similar FPWN values but different typical values.

(Why is home charging only 32 amps on SR when supercharging is so much faster?)

Anyway 2% works out to something like 53.5kWh*0.955*0.02= 1kWh.

Which over two weeks would be 70Wh/day. Nice and low!

Yep, not plugged in. We went to Mexico for 13 days and lost like 3% in that time, never checking the car via the app. I have the NCA pack.
Basically I won't even spend energy thinking about parking the car for up to a month as long as I left it with more than 30% charge. It's gonna be alright

 

[AlanSubie4Life]

Yep, not plugged in. We went to Mexico for 13 days and lost like 3% in that time, never checking the car via the app. I have the NCA pack.
Basically I won't even spend energy thinking about parking the car for up to a month as long as I left it with more than 30% charge. It's gonna be alright

So that would be an average of 120Wh/day, or about 5W.

 

[AAKEE]

Lower than I would expect (wonder whether new vehicles have lower drain than the older ones somehow).

Another possibility is that the BMS adjusted upwards before heading downwards. So rather than expected 20 (6%) miles you saw 6 or whatever. But only way to tell would be to check after parking for a while, before you leave.

Not sure if you ever have occasion to measure over a week or so (excluding initial transient). Hint hint. Lol.

Could be either. No idea if they have changed the hardware somehow to address the typical 200Wh/day loss. Or maybe I just haven’t measured recently and it is even lower than 200Wh/day for my car! Things are always changing.

Nope, I did check that also.

The initial SOC i refer to was the SOC after sleep. 33%.
The SOC after the our holiday trip was 31%.
It actually was slightly less than 2% loss, when looking with Scan My Tesla. I think I have the data for that.
Teslafi most often get whole number for percent (not always).

The charger was not connected (to protect from thunderstorm/lightning.

(my friend collected the car from the Service center (300 km away) the day before the trip. He's not a used EV driver so I gave him a slack from range anxiety, therefore it had 33% during our US trip.
If I hade driven, I would have set the target to arrive with 15% or so.)

One more thing, low SOC is also good for minimizing the self discharge.

I can add that teslafi reported 12 short periods of non sleep during these 18 days or so. In some cases it slept more than two days, and some days it had one brief awake period (charge the LV-batt?). Most days one or none awake period.

 

[AAKEE]

So that would be an average of 120Wh/day, or about 5W.

I calculated 3.47W for my car.

 

[AAKEE]

Heres one example of OVC variation with temperature:

And here is an example of self drain vs SOC: This picture if from a very old research report, but I only have this picture.
The lithium batteries of today could be different.

A resent article says the main reason for self discharge was not known before, but the reason was found and its possible to adjust the manufacturing process, virtually stopping the leak current.

 

[Edtreo]

Heres one example of OVC variation with temperature:
View attachment 904624

And here is an example of self drain vs SOC: This picture if from a very old research report, but I only have this picture.
The lithium batteries of today could be different.

View attachment 904625

A resent article says the main reason for self discharge was not known before, but the reason was found and its possible to adjust the manufacturing process, virtually stopping the leak current.

Tesla-funded researchers discover reason for lithium-ion battery discharges

A commercial tape that holds electrodes together in lithium-ion batteries can be the reason behind the self-discharging process.

www.teslarati.com

 

[AlanSubie4Life]

Interestingly the Energy Parked screen claimed a loss of ~10 miles in about a day for me. The prior instance of parking it, after the charge, it gained a few miles.

So charge (Supercharge) -> park -> gain a few miles -> drive around -> park at home for over a day -> lose about 10 miles.

Checked my 12V monitor and the car was sleeping the entire time of that long ~36-hour parked period (except for one very brief wakeup when I opened the door).

Really have to pay closer attention I guess. There are a few possibilities:

1) BMS adjustments
2) Errors in the Energy Screen (I wasn't paying close attention to rated miles at each point - though the driving Energy screen lined up with this data showing the jumps so I don't think it is this).
3) Some actual drain (seems virtually impossible since the 12V did not have a real charge cycle for something like 36 hours, and it doesn't have 10 rated miles of capacity!).

Anyway still seems like big jumps but I never pay attention to this anymore - and I do know that large adjustments are possible even without significant temp changes. That was not an issue at all in my case. Just typical temperatures ranging from 50 degrees to 70 degrees.

However, this was after a rare Supercharge so maybe that results in more BMS hunting, not sure.

Pictures show the supercharge around 7PM on the 9th, etc.

 

[Jon Humphreys]

The last two days my Tesla Model 3 has been losing excessive battery when in idle. The car is making a continuous loud humming noise (not the normal one when in idle). When I get in the car after it’s been sitting in idle for a few hours the temperatures will often say something ridiculously high (120–150 degrees F) despite it only being 70–80 degrees out. I have tried turning everything off while it sits in idle (sentry mode, cabin overheat protection, etc). Last night in an 8 hour period I lost 20% battery just with it sitting in park. I have no idea what else to do.

 

[AAKEE]

The last two days my Tesla Model 3 has been losing excessive battery when in idle. The car is making a continuous loud humming noise (not the normal one when in idle). When I get in the car after it’s been sitting in idle for a few hours the temperatures will often say something ridiculously high (120–150 degrees F) despite it only being 70–80 degrees out. I have tried turning everything off while it sits in idle (sentry mode, cabin overheat protection, etc). Last night in an 8 hour period I lost 20% battery just with it sitting in park. I have no idea what else to do.

Doublecheck, and tripplecheck that the sentry is not on. (Sentry would use 5kWh/24hrs so about 7% for a LR and 10% for SR/RWD)

Next thing is to perform a complete restart of the car, so it has not been kept from sleeping by a bug.

 

[TechSavySD]

As AlanSubie says Scan my Tesla shows battery temperature.
I also use teslalogger to log all SMT data.

I have a extra screen that show SMT data.
View attachment 899126

Is this a permanently attached accessory (vendor details??) or software running on some sort of iPad connected to OBD port?

 

[TechSavySD]

New 2023 M3LR Owner Questions:

I just took delivery of new M3LR yesterday. There are no Enhanced Ap or FSD options. I noticed 4% drop in battery energy overnight. Battery was charged to 90% at delivery and was about 80% after driving home. Car was parked inside garage. No WiFi connected. Sentry Mode was disabled. I have not received my mobile charger yet, so car was not charging.

When I checked on car a couple of hours after parking it, without unlocking it, I could hear a faint whirring noise coming from the front near the firewall. I speculated it might be heat pump still working to cool the battery.
Here in S Ca with June gloom, the temperature is consistently between about 55℉-65℉. The Cabin Overheat Protection was turned On, but I turned it off (it should not operate at these temps). After locking the car the whirring noise was still there and later when I came back. I saw some old posts from 2018 on other models to just ignore the whirring noise when car is in sleep. Being an engineer, I want to know what is constantly running and why, and how much power it is draining? I don't drive that much and definitely not every day.

Have I missed any settings related to this? I don't know how I could attach a dump of all my current settings. Just want to know if I am missing something obvious?

I have a service appointment this week for something else, so expect I can ask this then.

 

[AAKEE]

Is this a permanently attached accessory (vendor details??) or software running on some sort of iPad connected to OBD port?

It’s a Samsung tablet mounted on a 3D printed mount. I use Scan My Tesla to see all BMS-data. The tablet also sends all data to teslalogger so I get the datalogs home.

Scan my tesla use a extra harnes in the car plus a OBD dongle.

 

[AAKEE]

Have I missed any settings related to this? I don't know how I could attach a dump of all my current settings. Just want to know if I am missing something obvious?

I do not think so.

Summon is said to keep the car from sleeping, but that is a feature of the FSD.

Restart the car from the security tab in the menu, ”Shut down the vehicle”.
I would shut down the vehicle and not close or open any door after that selection was made. Do not touch the car at all. If you wait 8-10 minutes the contactors in the HV battery should say ”clonk” somewhere under the back seat.
After that the car is sleeping with no noice and no fans. (Just to test that it is able to sleep).
This shut down also forces most systems omboard to restart.