Vampire drain again?

[geometro]

Ok, it’s gotten colder here in TX but my battery dropped 5% last week (from 69->64%) while I went to the gym in the morning last week (was only in there for 50mins).

I don’t recall my car (2018, 40k miles) doing this in past winters. I submitted a service request and the response was not very useful (basically said it was “post drive upkeep”).

Anyone else experiencing something similar? Is this just software or something else?

 

[shahryaran]

How coolant level affected my range

I'm writing this post to help those owners who witness similar issues that I had with my range. The car: 2020 M3LRAB bought used from Tesla with 38K miles on it. Symptoms: 3%-5% charge drop while parked. Dramatic range drop while driving. AC not blowing cold enough. Fan running for a long time...

teslamotorsclub.com

 

[AlanSubie4Life]

Ok, it’s gotten colder here in TX but my battery dropped 5% last week (from 69->64%) while I went to the gym in the morning last week (was only in there for 50mins).

I don’t recall my car (2018, 40k miles) doing this in past winters. I submitted a service request and the response was not very useful (basically said it was “post drive upkeep”).

Anyone else experiencing something similar? Is this just software or something else?

BMS reestimation can be significant. You can track it with the Energy app. You’ll likely see increases as well. (It varies and depends on how accurate the BMS estimate is.)

5% is large but 2-3% increase or 2-3% decrease is not unusual I think.

 

[geometro]

Well, service is beyond useless they asked to communicate via email but have not responded to any of my communications. I did share the thread on coolant but they’ve gone silent.

I’m not keen on this approach— it’s very much a black box and I can’t really get a “second opinion”. My only hope is that a software update will fix this but otherwise I’m just in the dark.

 

[AlanSubie4Life]

Well, service is beyond useless they asked to communicate via email but have not responded to any of my communications. I did share the thread on coolant but they’ve gone silent.

I’m not keen on this approach— it’s very much a black box and I can’t really get a “second opinion”. My only hope is that a software update will fix this but otherwise I’m just in the dark.

I’d just use the energy screen. All the answers are there. If you see steps upwards too, you might find they all balance out. Consistent steps downwards will eventually result in a BMS adjustment with fewer rated miles at 100%, and then the problem will be reduced.

 

[geometro]

I’d just use the energy screen. All the answers are there. If you see steps upwards too, you might find they all balance out. Consistent steps downwards will eventually result in a BMS adjustment with fewer rated miles at 100%, and then the problem will be reduced.

Thanks. I have been looking at that and it seems to be random drops of 4-5% on various days. Have not noticed any jumps upward.

 

[jjrandorin]

Well, service is beyond useless they asked to communicate via email but have not responded to any of my communications. I did share the thread on coolant but they’ve gone silent.

Tesla service is pretty much going to ignore any "the battery!" discussion or complaint unless or until:

1. There are errors specific to the battery in the cars logs, or
2. The owner can demonstrate that the car meets the battery thresshold for replacement, which is 30% capacity loss from starting.

Pretty much anything else is not relevant to them, and due to the fact they likely get 100s "but my battery...." requests for information, there isnt much for them to disclose there.

They usually fall back into "we checked remotely and its fine" if it doesnt meet one of the 2 criteria above, because its the actual truth, generally. In the few times its not, it can take a long time for them to acknowledge or figure it out, because of the 100s and 100s of people clogging up communication with them about batteries.

 

[KenC]

Ok, it’s gotten colder here in TX but my battery dropped 5% last week (from 69->64%) while I went to the gym in the morning last week (was only in there for 50mins).

I don’t recall my car (2018, 40k miles) doing this in past winters. I submitted a service request and the response was not very useful (basically said it was “post drive upkeep”).

Anyone else experiencing something similar? Is this just software or something else?

5% is a big drop, but I see up to 5% increases and drops on a fairly regular basis, when there's a lot of temperature differential. In Summer, I see increases often, as I live on a lake, which has a cooling affect, so when I drive somewhere, and stop for a couple hours and park in the sun, I can see a 5% increase.

Just a quick look, and here's a 3% increase.

 

[ucmndd]

Well, service is beyond useless

There’s nothing for them to do. Nothing is wrong. Range and state of charge are estimates. Stop wasting their time.

 

[geometro]

There’s nothing for them to do. Nothing is wrong. Range and state of charge are estimates. Stop wasting their time.

"service" is in the name, I don't think it's wasting their time if something has changed (5% random drops when previously there were none) and it can't be identified easily by the owner. If my prior ICE car had excessive oil or gas consumption, I would know there is something wrong.

So glad you chimed in though.

 

[ucmndd]

If my prior ICE car had excessive oil or gas consumption, I would know there is something wrong.

Thats the nice thing about liquids. We can measure their volumes directly and it’s essentially unchanged by environmental conditions.

Unlike the amount of energy stored in electrochemical storage - which will ALWAYS be an indirect estimate and IS subject to environmental conditions like temperature.

Range is an estimate, as is state of charge. It will change over time. You’re asking a “service” organization to fix something when there’s nothing to fix and then calling them useless when they won’t.

They’ve given you the only answer there is to give.

 

[JCtx]

I remember our '21 M3 LR used to drop about 1% daily just sitting there, during winter storms (high temps in the teens for days), with the garage close to freezing. So about 7% per week. Reading about it here, it was deemed pretty much normal. EVs don't like the cold.

 

[Gasaraki]

"service" is in the name, I don't think it's wasting their time if something has changed (5% random drops when previously there were none) and it can't be identified easily by the owner. If my prior ICE car had excessive oil or gas consumption, I would know there is something wrong.

So glad you chimed in though.

Yeah, but even WE don't even know how to answer your question because there could be some many things that could have caused that issue that day. Maybe the car didn't go to sleep? Maybe the temp dropped a lot in that 50 mins? Maybe you have an app that kept polling the car? Etc Etc. I don't know what support is supposed to say other than " we looked at your battery, it looks ok to me".

 

[thatredM3]

BMS reestimation can be significant. You can track it with the Energy app. You’ll likely see increases as well. (It varies and depends on how accurate the BMS estimate is.)

5% is large but 2-3% increase or 2-3% decrease is not unusual I think.

I’ve never once seen it go up, only down.

 

[AlanSubie4Life]

I’ve never once seen it go up, only down.

Keep on looking. It definitely happens, and it's not rare (and it has done so for years).

 

[KenC]

Personally, I don't think people are noticing it. This image was from yesterday evening. My power has been out since Monday morning due to the big storm that blew thru here. After 3 ½ days my SOC was low enough, I decided to run some errands and stop by the local Supercharger to charge it up. I kept trips to a minimum during the outage.

As the storm came up the coast, due to El Nino, we got warm rain and winds. That raised the ambient the first two days, and if you look carefully at mile 30, which was Tuesday, the SOC was up. Then Wednesday and Thursday, the temps became frigid, and you can see, the SOC dramatically drops.

The way I look at it, the car's BMS when you start to drive, measures the pack's voltage based upon the ambient when you start to drive. It's not making any adjustment based upon ambient's until you stop, and start to drive again, wherever there's a vertical line. Because of that, you get adjustments, visible adjustments, between the time you stopped and the time you start.

To me, it follows a pattern of, is the ambient colder now than when you last started the car? Yes, then the adjustment is down. Or, is the ambient warmer now than when you last started the car? Yes, then the adjustment is up. It's that simple.

Just to be clear, you can see on the display, it shows it's 27F outside. A couple days before, when I drove from Mile 30 to about 45, it was almost 50F outside, much much warmer than even the previous day in the high 30/ low 40s.

 

[AlanSubie4Life]

To me, it follows a pattern of, is the ambient colder now than when you last started the car? Yes, then the adjustment is down. Or, is the ambient warmer now than when you last started the car? Yes, then the adjustment is up. It's that simple.

I’ve seen it change several miles in just a few minutes (15-30 minutes after a sleep cycle or something). Posted about it I think. So it isn’t just temperature. It’s possible temperature change has an effect but it isn’t required.

 

[jnhashmi]

Tesla service is pretty much going to ignore any "the battery!" discussion or complaint unless or until:
2. The owner can demonstrate that the car meets the battery thresshold for replacement, which is 30% capacity loss from starting.

Hi jjrandorin. Can you explain what "30% capacity loss from starting" means? I charged to 80%, then drove 137 actual miles. My M3 showed a 196 mile decrease in range. That's a 43% "loss" of range! Can all that be explained by the heater being on or other systems? (I am in Los Angeles.) Trying to figure out if I've got battery issues that I should worry about?

 

[jjrandorin]

Hi jjrandorin. Can you explain what "30% capacity loss from starting" means? I charged to 80%, then drove 137 actual miles. My M3 showed a 196 mile decrease in range. That's a 43% "loss" of range! Can all that be explained by the heater being on or other systems? (I am in Los Angeles.) Trying to figure out if I've got battery issues that I should worry about?

It has nothing at all to go with what the range meter rolls off vs what you drive (zero). There is nothing wrong with your car.

To answer the question, what 30% loss range from starting means is, a 30% loss of the RATED range from when the car was delivered. You would take the rated range that your car had when it was delivered, and see what 30% of that is, and subtract that number from the rated range, and when your car CHARGES to that range or less, then you have a claim. otherwise, you dont.

If your car was delivered with 320 miles of range, 70% of that is 224, so when the car CHARGES to 100% at 224 miles, then you have a range issue you can take to tesla.

What miles roll off the car when you drive dont figure into this at all.

I charged to 80%, then drove 137 actual miles. My M3 showed a 196 mile decrease in range. That's a 43% "loss" of range! Can all that be explained by the heater being on or other systems? (I am in Los Angeles.)

Weather, and elevation changes, and heating use, yes, it absolutely 100% can.

 

[AAKEE]

A add on to this thread about State of charge (SOC):

State of charge is not an estimate when the car is parked and has been sleeping for a while.

The SOC is defined by the open circuit voltage. The BMS has a table where each OCV equals a specific SOC.

So as long as the car is sleeping the SOC is very precise (LFP’s do not count here).

Actually, after parking the car, before it falls to sleep (get to measure the OCV) the SOC is adjusted ”roughly” but this rough adjustment is much more exact than the whole percent displayed in the car.

During a drive though, the SOC can not be measured. So the BMS use the estimated capacity + the SOC to calculate the energy onboard.
Displayed (estimated) SOC is
(energy onboard - use energy)/estimated capacity.
Wrong estimated capacity will render the estimated SOC to be wrong and to need to be adjusted when the SOC can be measured (when there is virtually no load on the battery or prefered OCV).