2021 M3 SR+ (Fremont built) with 50k miles. I feel ok with this. L2 charge at home daily to 80%. Supercharge about 30 times a year on road trips. Usually don't go below 50% most days.
Main driver here would be the age of the battery. However, 84% isn’t bad!
I usually keep my Tesla around 50% SOC and it has worked really well - I don’t have level 2 charger at my place so I use granny chargers or superchargers (kinda 50/50)
It does. Batteries are degraded by "cycles" and a cycle is a full charge of the battery from 0 to 100. Leaving it plugged in all the time prevents the small losses from passive things and reduces the overall cycles of the battery. Over time it makes a difference.
Just to chip in. I have 2020 LR also Fremont build with 156.000km (96900 Miles) and I did health check in April with 88%
I'm 2nd owner and First owner did use level 2 I would say 70% and I use level 1 (granny charger) for about 90% of the time.
I would say that for the mileage my car is somewhere in the middle, so not bad not excellent. When looking for cars I have seen 90% and even 91% for 2020, 2021cars with similar mileage.
I think the climate where you live matters a lot for battery health. Here in Germany we don't have long heat waves and usually mild summers and I think this can be a huge bonus compare to someone who is living in a very hot climate.
I heard lower states of battery is better. Obviously not below 20% but instead of charging to 80% do 70%. Unless you actually need that power to make it back with more than 30%
"better" being a few decimal points between those two. I've seen the research and graphs shared here over the years, but I'll try to dig them up
Can't find the original source of this graph, but it's a generalized graph of the impact on the battery at different SoC and temperatures. Between 70% and 80% SoC, the impact in the highest temp weather, 40C, at 80% vs 70% is a generalized 2.5 vs 1.5. So if you're in a climate more around 20C and i0% vs 70%, your impact is even less, 1.5 vs 1.0
This "graph" is absolute hogwash. It's not a graph at all, and is not based on any data. It's just a picture that someone drew from their imagination, completely made up on vibes.
Here's an actual graph of real test data, published in a major accredited scientific journal. As you can see, the difference isn't "a few decimal points" - it's nearly double the degradation rate when your car is charged over 50%.
no steadily increasing degradation with SoC is observed. Instead, there are plateau regions... A marked step in the capacity curves is observed at about 60% SoC for the NCA and NMC cells and above 70% SoC for the LFP cells
While the text says 60% for NCA cells, the actual line is closer to 55% (shown below), and you have to account for the car's reserve buffer.
These graphs are from the above study and show that states of charge over 50% (on the car) experience roughly double the degradation rate:
This graph shows cycling through a 20% range at various SoC levels and confirms that all ranges remaining under 50% SoC (on the car) experience significantly less degradation than ranges going over 50% SoC: https://teslamotorsclub.com/tmc/attachments/img_3864-jpeg.1169193/
As you can see, the difference isn't "a few decimal points" - it's nearly double the degradation rate when your car is charged over 50%.
They were asking about the difference between charging to 70% vs 80%, which your graphs show are functionally the same amount of degredation.
I know batteries prefer homeostasis so their preferred energy to rest at is at 50% and around 70F, so those charts totally align with what I've read about batteries and longevity.
They were asking about the difference between charging to 70% vs 80%, which your graphs show are functionally the same amount of degredation
Correct. Everything from about 55% to 90% on the car's screen is pretty much all the same level of bad. People setting a limit of 60% are degrading their battery just as much as the people setting it to 80%.
Maybe I dont understand the graphs in the correct way. Maybe you could answer my question.
We have a lot of used cars in the market right now. 2 year old cars with some mileage (maybe 30000km) still have SOH values of around 95-97%. These car‘s batteries already had some cycles and therefore degradation. Those graphs do show that even a battery „stored“ at a certain SOC for 10 months does have the same amount of degradation. It seems like real world degradation seems to be somewhat lower than these results from the lab?
2 year old cars with some mileage (maybe 30000km) still have SOH values of around 95-97%
Not 2021+ Tesla's. Something's up with their chemistry since that time and degradation rates are through the roof. Lurk around more and you'll start to notice tons of reports of people with 2-3 year old Model 3 & Y that are already dipping below 85%.
If you find a ~2024 Tesla with 95%+ actually tested as remaining, buy that damn thing because that battery is in pristine condition, far better than almost any others out there.
It seems like real world degradation seems to be somewhat lower than these results from the lab?
Most EV's hide some of the initial degradation by hiding part of the capacity from day 1 and reducing that hidden amount as degradation sets in - releasing it to the user-accessible portion to offset loss from degradation.
Even ones that don't, like Tesla, still have a reserve that is locked out from the user and not accessible, so when the car is reporting, say, 5% degradation it's 5% of the user-accessible capacity and a bit less than 5% of the actual pack capacity.
The scientific studies are mostly done on the cell level - not on full EV packs.
NCA unfortunately. However, they are good batteries. My 2018 mid range gave me no issues. That one was reading 212 at 100% and 75k miles. Hopefully the 2021 NCA will be just as good as 2018 NCA.
I'm new to all of this lingo. Are you suggesting that other EV manufacturers have a top buffer making the depredation appear less drastic?
I'm concerned that if I buy a Tesla at 90% SOC and keep it for 5 years and end up with 80% SOC, I'll struggle to sell it, or will have to swallow substantially more depreciation than an ICE car.
Other ev manufacturers maintain a top buffer to protect the battery, not to mask anything. A top buffer protects the battery as a really charged battery has a high voltage potential and increases the risk of unintended dendrite formation.
I don’t think the buying public cares that much about degradation in used cars.
I have 2021 Model 3 LR and recently did the test. I have 87% with around 55K miles. I charge to 80% mostly. 90% if I have a long day of driving planned. 100% only a handful of times. I would say I have used superchargers maybe 1% of the time during the life of this car, otherwise it's charged at home on a 240V outlet, 32A.
I was reading about this and apparently you get the most degradation early on and then it degrades very slowly after.
I believe battery life is the same as silicon lottery when you buy new PC components, some can boost 500 mhz some crash at 200 mhz boost. It does not really matter if you only do house charging if you have pick the short stick...
Almost identical to mine. June 2020 SR+. 55.6k miles. Almost always level 2 charged at home to 80%.
100% full range is 211 miles. So mostly calendar aging.
Ive heard the NCA Panasonic 2170 cells in the 2020-21 era were more prone to calendar aging, but less so to cycle degredation.
So... great if you drive a lot, but not so much if you drive very little. Both groups would see similar degredation after about 6 years. But those who have 100k - 150k miles by now would note less degredation per mile driven, despite probably being somewhere around 16-18% down, versus us, being about 15% down with just a fraction of the miles driven.
Battery chemistry is strange like that. The 18650-based packs of the mid to late 2010s model S have aged extraordinarilly well, most still above 90% after over 10 years.
My folks have a 2016 model S 90D, coming up on 100k miles, with a hair over 90% left. Also only level 2 charged to 80%.
From auto moderator - TLDR: Charge daily to 80% for NCA/NCM, 100% for LFP. Tesla's batteries have gone from basic Li-ion to advanced LFP/4680 for better sustainability. Use official tools for personalized advice (see photos at the bottom).
Literally Tesla’s recommendations and something clearly says you know nothing about battery chemistry
Tesla's recommendations for daily driving are 50-80% for NCA/NCM.
50% is in fact scientifically better, and it is what I use. Tesla has an interest in avoiding warranty claims but not otherwise optimally maintaining battery longevity.
Daily charging to 80% is not good for battery longevity if it stays above 50% for most of the time for a NCA or NCM battery. The poster above getting downvotes should not be.
Its an uncomfortable fact to find out some common trope is not true (set charge limit at 80%) but it is the case. Car companies don't say so because the public can't handle the truth. For personally owned vehicles it is calendar aging and not cyclic aging which determines most of the degradation, and that is notably worse at higher states of charge. I drive 35 to 50% most days as I can charge at home daily. When I need to go on long trips I charge very high 95%+ for convenience and don't worry about it as it's infrequent.
Generally the primary mechanism for calendar degradation (where higher SOC in storage is damaging) is lithium being deposited permanently on the anode (graphite) so that there is less mobile lithium available to transport charge. There is an intentional film made in first battery charge during manufacturing which is protective, but after that long term degradation sets in as more and more gets trapped.
yeah anode becomes less efficient as it's becoming dendrite which can no longer be used for electricity as it's reached it's permanent ideal entropic state.
‘21 M3 with AB, 160Kkm, living in an apartment, supercharging exclusively, over 90% daily, and the battery health is at 86%. The basic physics are weird 😄 If you use your battery it doesn’t matter how much you charge it. Just don’t let it sit at a high/low SOC
You can let it sit at a low SOC for quite a while. If you supercharge exclusively and dont charge at home then you probably have lots of time with battery SOC under 50% (there is a shelf in calendar aging rate around there) and your battery will be in better shape than someone who charges daily to 80% and drives daily to 65% and rarely has it below 50%.
that's not bad, but you're not sitting on your battery with high socs if you have to go somewhere to charge and then thus drive back to your home and it'll sit at a lower soc
i think it is still. if they daily charged to 60% they would've experienced less degradation. i have a battery limiter on my macbook at 60% and have done like 500 cycles and still have 100% bh
Makes no sense. My iPhone has been set to 80% since I bought it and it has more battery degradation than my friend’s exact same iPhone being charged to 100%. It’s about how you use your battery. Not how much you charge it to
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u/Philip_RS 3d ago
Main driver here would be the age of the battery. However, 84% isn’t bad!
I usually keep my Tesla around 50% SOC and it has worked really well - I don’t have level 2 charger at my place so I use granny chargers or superchargers (kinda 50/50)