Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[jyavenard]

Exact how do the car tell you that low SOC is bad for the lithium battery?
I would say that you have seen information in your car from that you have drawn your own conclusions( that might not be right).

If you read the manual it clearly states that the 12V battery might get damaged if the SOC gets so low that the lithium battery stops charging the 12V battery. ( 12V lead batteries is sensitive to low SOC, and sulfates if discharged.)
There is no warning at all in my Tesla manual to leave the car at low SOC, except that not leave it so the battery goes below 0% SOC. A rule of thumb of 1% per day is used to help cslculate the loss during longer time.

Tesla says ”Below 90%” in the manual. They do not sat ”90%” or ”80”.
You might wanna look at what advice Tesla avtually gives.

Tesla of course give us a as big window of usage as they can, to make the life easy, and at the same time not cause too much degradation. The 90% daily rule doubles the battery life, so thats a good reason.

There is no information in the manual that states or implies that low SOC is bad for the lithium battery. There also no such info in the car. The low power at low SOC comes from the reason that lower voltage gives lower power (P= U x I ), and that the internal resistance increases at low SOC icreases a lot ( again, P= U x I).

There really is no way for Tesla to use the NCA Battery technology and get around the law of physics that applies to the NCA technology as we know it today. In many of the research reports the cells tested was panasonic NCR cells, very close to Tesla cells and in some cases more or less panasonic Tesla cells.

You are of course entitled to your own approach to your charging habits.

Do we have such degradation graph according to SoC for LFP batteries?

How would that compare with the batteries found in LR and Performance models?

 

[AAKEE]

Do we have such degradation graph according to SoC for LFP batteries?

How would that compare with the batteries found in LR and Performance models?

Yes, there is. There is one recent research which on a little shaky grounds( few measuring points) imply that LFP has least calendar aging at 100% SOC. All other research shows about the same behaviour as NCA and NMC.
The Tesla advice to charge to 100% with the LFP probably origins from the very flat voltage curve and the risk of BMS drift.
But there is a probability that the latest LFP cells Tesla use (CATL) behaves different, so some uncertiness until we have data from usage. The cyclic aging is very small so we should know soon.

All LR and P cars had Panasonic NCA until about one year ago. Tesla started to use LG NMC in some LR model 3 for EU. initially there was a mix of batteries in EU LR but from now i think all EU LR get LG NMC.
Model 3 Performance will change to LG NMC as well, soon.

 

[Stan930]

Was the AB removed from purchase on the new M3LR with the LG Pack?

 

[snowthewitch]

It's been extremely cold temps, I charge and precondition in my garage to 90%.

What is being indicated on the graph? I see avg 390 miles or something on the far left but on the right side is shows 160 miles.

Trying to determine efficiency, but these past few mornings I drive to the gym and back like 20 miles (~10 each way very close) and I go from 90% -> 78%.

Basically, what's the graph showing and is this the expected loss?

 

[AlanSubie4Life]

Is this normal? Even though it’s cold? I

Have to post the Wh/mi, for a segment without time spent in park. And the other details (distance, rated km used).

Probably normal though. Maybe 300-400Wh/km on a very cold, windy day going uphill or whatever.

If you post the stats (all the stats!) it is easy to assess.

Every now and again things are “not normal,” so we’d need more data to say definitively one way or another. Usually everything is fine though.

 

[snowthewitch]

Have to post the Wh/mi, for a segment without time spent in park. And the other details (distance, rated km used).

Probably normal though. Maybe 300-400Wh/km on a very cold, windy day going uphill or whatever.

If you post the stats (all the stats!) it is easy to assess.

Every now and again things are “not normal,” so we’d need more data to say definitively one way or another. Usually everything is fine though.

Thanks, it's recorded a bunch of 'park time' so I'll get a fresh set tonight/tomorrow. Was planning to drive 60 min tomorrow and then leaving it parked there for ~10 hours and driving back. Concerned if I'll make it back.

M3LR

 

[robl45]

Your car battery, displayed using only the information on the car itself, not any third party app, will need to display a capacity at 100% that is at least 70% less than what you started with. Your car likely started with 310 as a 100% range, and 70% of 310 is 217.

So, your 100% charge will need to display 217 before you can go to tesla talking about battery warranty.

I also know you have been here and read enough threads on this topic already to know that "I went 44 miles and it has 184 miles left" doesnt mean much as far as battery capacity goes.

I have, however now it appears to be extreme. I start at 241 miles now with 90 percent charge and go 44 miles and I"m down to 84 miles. Realistically, I'm probably already at less than 200 miles.

 

[diamond.g]

I have, however now it appears to be extreme. I start at 241 miles now with 90 percent charge and go 44 miles and I"m down to 84 miles. Realistically, I'm probably already at less than 200 miles.

You drive 44 miles in one trip and now your display says you can only go 84 more miles?

 

[AutomaticMan]

I realise I'm going to get slammed for this thread with "do a search, there are a million threads already!" and "read the manual!" So I apologise in advance I actually have read the threads and bits from the manual, but there's a lot out there about this so I just wanted to quickly double-check I've understood this right. A few "yeah, you've got it" replies as confirmation is all I need then I'm happy to let this thread die (or be deleted if the moderators want to?).

I have a M3 LR on order and I will never, ever need to charge it to 100% for range purposes. I should say here before someone asks why I don't get a RWD, I'm actually not getting the Long Range because of the range... I'm getting it for AWD, performance, and premium audio. I see that it seems a pretty settled consensus that there is no reason to ever charge it to 100% in that case. It also seems pretty settled consensus that you should plug in every night if you can charge at home, which I can.

Where there seems more debate is whether your every day charge limit should be 80% or 90%. So for that reason, I'm thinking about covering my bases by taking the following approach to charging. Please can someone let me know whether this seems like a good approach?

• Set my normal day charge limit to 80%
• Plug in every night
• The night before I'm going on a long trip, change the charge limit to 90% for that overnight charge

Thanks!

 

[Amped412]

Yep, you got it. It’s as simple as that

 

[AutomaticMan]

Yep, you got it. It’s as simple as that

Thanks!

(Mods - happy for you to delete this thread now if you don't think it adds any value)

 

[jjrandorin]

I realise I'm going to get slammed for this thread with "do a search, there are a million threads already!"

Not really, you are just going to get your thread moved into one of the existing ones, like I have done here.

 

[CarlThompson]

It also seems pretty settled consensus that you should plug in every night if you can charge at home, which I can.

Actually, it's no longer quite as settled that you should plug in every night because of potential BMS inaccuracy / drift from it not seeing the battery at low states of charge enough. Many people who don't drive a ton every day are reporting that eventually the car's reported range will go down more than it strictly should due to degradation because of it. I believe I may have had this issue in my first Model 3 which I charged every night.

While definitely not a consensus, there is a new school of thought that it actually might be better to get an accurate range reading to just charge when you get down to 20% or so or when you need it. That's the approach I plan on taking when I get my new 3.

 

[CRACKLING ROSE]

I have a new model 3 standard range and so far havr traveled 1400ks.I wa s looking at the average power use ,it is showing 133 wh/km.Is this about right ?
Cheers Colin

 

[jjrandorin]

Actually, it's no longer quite as settled that you should plug in every night because of potential BMS inaccuracy / drift from it not seeing the battery at low states of charge enough. Many people who don't drive a ton every day are reporting that eventually the car's reported range will go down more than it strictly should due to degradation because of it. I believe I may have had this issue in my first Model 3 which I charged every night.

While definitely not a consensus, there is a new school of thought that it actually might be better to get an accurate range reading to just charge when you get down to 20% or so or when you need it. That's the approach I plan on taking when I get my new 3.

Thats not better for the battery, thats better for the display on the screen of range. When people see that drift you are talking about, its not actual loss, its the number on the screen reading lower. There also isnt any school of thought that says its better to run it down and then charge it back up on a regular basis.

It might be helpful to the BMS for calibration to do that "occasionally" but its not "better". "Better" would be to set it to about 50% and keep it around there, unless you need more or less (huge summary with this statement though).

In any case, running it down to charge it back up on a regular basis is not something that needs to be done.

 

[CarlThompson]

Thats not better for the battery, thats better for the display on the screen of range. When people see that drift you are talking about, its not actual loss, its the number on the screen reading lower. There also isnt any school of thought that says its better to run it down and then charge it back up on a regular basis.

It might be helpful to the BMS for calibration to do that "occasionally" but its not "better". "Better" would be to set it to about 50% and keep it around there, unless you need more or less (huge summary with this statement though).

In any case, running it down to charge it back up on a regular basis is not something that needs to be done.

I didn't mean to imply that letting the battery run down to 20% or so before charging when convenient to do so is better for the battery itself. (Though it is a little bit better for it than charging to 80 or 90% every night.) I meant "better" in the sense that the car will be able to give its owner a more accurate reading on the battery's remaining capacity by giving the BMS more data points at different levels to work with.

As for 50%, I have read nothing anywhere that suggests there is anything magical about that particular number. 50% is still technically worse for the battery than say 40% or 30% but of course by a tiny amount. To balance utility with longevity it's probably "better" all things considered to charge the battery to 80% or even 90% when it is charged so that you have the range conveniently available when you want it even if doing so may reduce longevity by a small amount. Of course, that's just my opinion and each individual owner will have to decide for themselves how important a tiny bit more longevity is vs. convenience. But charging it up higher when you do charge also helps the BMS have an accurate idea of what your battery's remaining capacity is. Not charging it up to reasonably high level often enough can lead to the same problem as not letting it run down to a low level often enough.

 

[neuralnet]

Took a couple of very cold drives yesterday (from and then to home) and was amazed at how much of an impact it has on the efficiency. Probably 80% highway driving around 60-65mph. Driving careful with snowy/icy conditions and passengers in the car. Here's data from TeslaFi

Drive one:

Drive 2. First portion was pretty snowy on the ground so took it slow:

This is in a June delivery 2021 Model 3 LR.

Go Bills!

 

[airheadmax]

Given the recommendation to minimise time on SOC > 80% and supercharging, what would be better best practice for a given trip:

A: Charge to 100% and leave immediately (no supercharging)
B: Charge t0 80% and supercharge at least 20% during the journey

 

[LoudMusic]

Personally I'd charge to 100% at home and not charge during the journey. Maximize the convenience of an EV. Charging to 100% occasionally isn't a bad thing. Don't let it sit at 100% for hours and hours.

 

[jjrandorin]

Given the recommendation to minimise time on SOC > 80% and supercharging, what would be better best practice for a given trip:

A: Charge to 100% and leave immediately (no supercharging)
B: Charge t0 80% and supercharge at least 20% during the journey

People fixate WAAAAAAYYYYY too much on this. The recommendation for both of those things is "on a regular basis". Think of it like drinking alcohol or something. Having a few drinks a week is perfectly fine (but perhaps not "quite" as good on your body as never, ever touching alcohol).

Having a few drinks a day is not something anyone would recommend, on a regular basis anyway.

Charging to 100% sometimes (when going on a trip) is fine. Supercharging sometimes (when needed) is fine. Neither one of those things is going to make a single bit of difference in your ownership of the car or its battery. Do whichever one is more convenient for you, thats it.