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

[AlanSubie4Life]

what is this degradation threshold you’re referring to?

@conv90 has explained the term clearly. It’s just a term I came up with to explain this observed behavior.

To complete the picture, necessarily the way this works is as capacity loss occurs, each displayed rated mile gradually contains less energy (so they tick off slightly more quickly) until the vehicle full battery capacity reaches the threshold, whereupon their energy content becomes fixed (and instead, you start showing capacity loss).

This mechanism has been well verified by hard data from SMT and simultaneous Energy Screen captures on new vehicles (the only way to see the behavior easily though to a VERY careful observer it can also be verified from the trip meter as a car ages).

 

[jjrandorin]

Model 3 performance 2019. Went 44 miles today and better saying 184 miles left. How much does it need to go to be at warranty level? Avg 288 watts or whatever. Just seems lower by the day and I hammer it

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.

 

[ran349]

So best charging practice would be to 90%? Should I plug it in only once a day (after I’m done driving for the day) or whenever I can (every time I park it). Also reading controversies ideas on this.

I think there is no need to plug in every time you can. I plug in once a day at the end of my driving for that day. The exception would be only if you think you might need more to get you through the day. I charge at night when my electrical rates are at the minimum.

 

[jjrandorin]

Having read thousands of posts, on this 3 forum, I think the number of instances of HV battery failure requiring any part of a pack to be replaced may be less than the fingers on one hand. You should check with the forum moderators, as they probably have read more posts. I used to have a 2016 Chevy Volt, and in the 3yrs I owned it, the forum I visited, there were definitely more battery packs replaced than in this 3 forum. Of course, it's all anecdotal, but HV pack replacement doesn't seem to be an issue. The probs seem mostly to be cosmetic and aesthetic ones, vs mechanical, though premature 12v battery failure seems fairly common.

My reading experience here mirrors what you are saying (number of instances of HV battery in a model 3 failing are very low). There have been threads with people replacing them because of damage. I cant remember a single thread where one has been replaced due to degradation (in a model 3) but there likely is one or two somewhere.

Model 3s are only at most 4 years old this point, maybe we will see more of this in the next few years... and yeah 12V failure after 2 ish years seems very common, by contrast.

 

[jyavenard]

Well, the first bold is not correct. You might think we all know, but thats most probably a dunning krüger effect. I do not say this to be rude, but in a himble way because that most probably a fact.

Yes, I say *definitely* because of the few warnings given by Tesla, having a very low SoC is probably the most vocal/loud

As soon as you reach a SoC below 10% you start getting warnings; under 8% the car starts to limit how much you can accelerate; the lower it gets the more insistent the car tells you that permanent damage could be caused to the battery.

So you may have read heaps of paper stating otherwise, but I will go with why the car tells me and to never leave it at a SoC below 10%.

So when I see graph saying 0% is best; it’s very much at odds with Tesla advice

 

[malla2514]

Same for me as well, range locked at 220 miles.
Took my new Jun’2019 model 3 SR+ to Tesla service center but they said everything seems fine with battery and range.
No resolution after calling customer support.
Charged 100%, no luck with recalibration.

Even though paid for SR+, got SR configuration. Really disappointed, as the range further got dropped 10% or so till Jan’2022.

 

[Olegred]

I set it up so that when I press a button on my phone before the trip, the car wakes up, starts, turns on hvac. I also start charging to top off a few miles I lost after the night charge. Do you think it is okay for the battery in the long run? I usually turn on the car about 15 or 20 minutes before I leave.

 

[Sophias_dad]

It'll have no affect on the battery in the long run.

 

[kavyboy]

I set it up so that when I press a button on my phone before the trip, the car wakes up, starts, turns on hvac. I also start charging to top off a few miles I lost after the night charge. Do you think it is okay for the battery in the long run? I usually turn on the car about 15 or 20 minutes before I leave.

That's what the top 10% is there for - to be used if you need it.
You'll likely sell or otherwise get rid of the car long, long before there's any meaingful or even measurable, change by using that top-off amount.

 

[Olegred]

Thank you. Should I reduce the amperage of the short term charge? Or should I keep it at 48 amps?

 

[jjrandorin]

Thank you. Should I reduce the amperage of the short term charge? Or should I keep it at 48 amps?

There is no benefit to reducing the amps (all home charging is slow to the car, including 48amps).

 

[AAKEE]

Yes, I say *definitely* because of the few warnings given by Tesla, having a very low SoC is probably the most vocal/loud

As soon as you reach a SoC below 10% you start getting warnings; under 8% the car starts to limit how much you can accelerate; the lower it gets the more insistent the car tells you that permanent damage could be caused to the battery.

So you may have read heaps of paper stating otherwise, but I will go with why the car tells me and to never leave it at a SoC below 10%.

So when I see graph saying 0% is best; it’s very much at odds with Tesla advice

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.

 

[Alicehaydawn47]

So I bought a 2021 Model 3 SR+ (With the heat pump!!) in September of 2021. This is my first winter with it so I’m pretty new to all this, and I live in Norway so temperatures reach down to -8.

But it’s about a 40km drive to my work from home and I drive at a speed between 80km/h-100km/h . I lose about 100km range on that 40km drive.
I also lost ab 80km range today on a 20km drive even though I stopped and parked once. Speed was at 30km/h downtown and 100km/h at the highway.

Is this normal? Even though it’s cold? I expected to lose some range during winter but now over half of the stretch that I drive.

Should I get this checked out or is this normal? I’m kinda stressed there is something wrong

I’m also good with keeping the battery health, pre heating the car while plugged in etc.

Thanks for answers!

 

[jjrandorin]

So I bought a 2021 Model 3 SR+ (With the heat pump!!) in September of 2021. This is my first winter with it so I’m pretty new to all this, and I live in Norway so temperatures reach down to -8.

But it’s about a 40km drive to my work from home and I drive at a speed between 80km/h-100km/h . I lose about 100km range on that 40km drive.
I also lost ab 80km range today on a 20km drive even though I stopped and parked once. Speed was at 30km/h downtown and 100km/h at the highway.

Is this normal? Even though it’s cold? I expected to lose some range during winter but now over half of the stretch that I drive.

Should I get this checked out or is this normal? I’m kinda stressed there is something wrong

I’m also good with keeping the battery health, pre heating the car while plugged in etc.

Thanks for answers!

Should you get it checked out? No. Normal to use more than kms than you travel? Yes. Is this exacerbated in the cold? Also yes. For more than that, you can read through this thread I moved your post into.

 

[sunhead21]

Yes.

We know from the research that small cycles is good. The smaller the cycles, the longer the battery life will be( when it comes to cycles). Research use the term EFC, Equivalent Full Cycles( meaning 10 cycles with 10% dept = 1 EFC).

So you should charge every night if possible.

Calendar aging is causing the greatest degradation for most cars the first five years. Keepin the SOC low reduce the calendar aging. If you do not need 80% you could charge to 55%. Even better if this is done just before driving instead early in the evening(causing higher SOC all night).

These small cycles also cause much less wear if they are low in the SOC range.
6000 10% cycles(600 EFC) around 70% SOC (ie 75-65%) caused 10% degradation but 6000 10% cycles around 30% caused only 2-2.5%. Thats the same energy, same miles used but much less wear on the battery.

So:
-Stay low (55% or lower preferably)
-Charge “just in time”
-Charge often-> small cycles.

With these actions taken, the degradation will be very low, and one can happily Supercharge and charge to 100% when the need comes

Thanks a lot @AAKEE for your detailed and thoughtful response.

Also would you recommend that I keep my charger plugged in when not in use to maintain the charge at 55%. I believe that this is what Tesla is recommending - but not sure whether it has any effect on the battery degradation.

 

[Alicehaydawn47]

Should you get it checked out? No. Normal to use more than kms than you travel? Yes. Is this exacerbated in the cold? Also yes. For more than that, you can read through this thread I moved your post into.

I knew that it was normal to use more kms than I travel, I just didn’t expect it to use more then twice the range I’m driving. It just made me a bit stressed thinking there were something wrong. Thanks for the reply tho!

 

[AAKEE]

Thanks a lot @AAKEE for your detailed and thoughtful response.

Also would you recommend that I keep my charger plugged in when not in use to maintain the charge at 55%. I believe that this is what Tesla is recommending - but not sure whether it has any effect on the battery degradation.

It probably doesnt make a big noticable difference when it comes to degradation.

The most probable cause for Tesla stating ”Always connect” is to make us charge more often which give us smaller Dept of Discharges which in turn keeps the degradation down.

I always connect my car when I park in my garage, but I have scheduled charging set to commence between 0330 and 0430 each.

 

[CarlThompson]

I knew that it was normal to use more kms than I travel, I just didn’t expect it to use more then twice the range I’m driving. It just made me a bit stressed thinking there were something wrong. Thanks for the reply tho!

It's normal to get less range than rated in a Tesla. Particularly in the winter and of course Norway is worse than most places.

That said getting less than half the rated range sounds worse than it should be in normal cold conditions particularly if you are maintaining a speed between 80km/h and 100km/h as you say. Was the road and the weather clear or was it snowing or raining at the time? Was it very windy? Did you preheat your vehicle? Were you driving normally or were you driving in a "spirited" fashion? What cabin temperature did you have set?

Your 2021 car has a heat pump I think but at -8C it wouldn't be effective so it may have been using that energy plus resistive heating as well to warm the cabin. Hopefully the car is smart enough to just skip the heat pump entirely at those temperatures. -8C is cold but it's not that cold compared to what others have driven in and gotten better efficiency. Especially if you truly were maintaining a reasonably steady 80km/h to 100km/h then that doesn't seem right. In my experience when it's cold and you need to use cabin heat the speeds you were traveling are the MOST efficient so it's odd you got such poor efficiency.

If it was just a normal but cold day and if you were driving in a normal fashion then yeah I myself would ask Tesla politely to check the car just to make sure there's nothing wrong. Just tell them what you told us here and be very polite and tell them you got less than half the rated range which seems high. It doesn't hurt to ask and they can check the car's logs remotely.

 

[WhiteWi]

Sooooo After 2k round trip supercharging any where between 8-15% to 75-85 and my car sitting for few days at 120v charger at parents in law (plugged in below 20%), then upon return arriving to my house at the end of the trip with 11% plugging in at 12pm but didn’t start to charge until 12am same day. My car was showing for half a year 279-280 miles at 100% and now it went all the way up to 290 miles. Sweet.

 

[KenC]

So I bought a 2021 Model 3 SR+ (With the heat pump!!) in September of 2021. This is my first winter with it so I’m pretty new to all this, and I live in Norway so temperatures reach down to -8.

But it’s about a 40km drive to my work from home and I drive at a speed between 80km/h-100km/h . I lose about 100km range on that 40km drive.
I also lost ab 80km range today on a 20km drive even though I stopped and parked once. Speed was at 30km/h downtown and 100km/h at the highway.

Is this normal? Even though it’s cold? I expected to lose some range during winter but now over half of the stretch that I drive.

Should I get this checked out or is this normal? I’m kinda stressed there is something wrong

I’m also good with keeping the battery health, pre heating the car while plugged in etc.

Thanks for answers!

Seems a bit much to me; as I lose less than 20% efficiency when the temps drop from 80F to 20F. Then again, I'm more likely to pre-condition and to keep the interior temps low, 65F to 68F, and use the seat heater first. My 3 is in a carport, so I wear my Winter coat when in the car, so I use less heat in general. Still, my efficiency drop is quite small, nowhere near 50%.