E90alex
Active Member
Sure but I don’t find it to be a huge difference and more than fast enough. I’m not driving on a timed drag strip throughout the day. It’s still more power than what you get in Chill mode with a full battery.
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Favor Low SoC or Small Cycles?
- Thread starter Drinyth
- Start date
No, thats not correct.
Several of the studies I have linked to has used Panasonic NCR18650 (either NCR18650B or PD), thats a Panasonic NCA cell very closely related to the cell that is/was used in Tesla model S. These have the same energy density as The panasonic NCA cells (NCR18650) used in Tesla model S/X. Without specifically getting the hand on Tesla cells, these are as close as we can get to using tesla cells of 18650.
For model 3 and Y the chemistry was initially more or less the same, only the form factor was changed. The later Panasonic 2170L that I have in my M3P also seems to follow the same lines as the earlier 2170.
(I have 35 Panasonic 2170 Tesla cells that I use for own tests. So far, these seem to age about the same as the graphs i have posted about NCA cells.)
As all lithium batteries except some special chemistries not discussed here have about the same behaviour for calendar aging, and all research about NCA chemistry show about the same calendar and cyclic aging it is very probable that The PAnasonic NCR cells Tesla put in their cars also behave the same.
The branch standard is that a lithium battery life is said to be down to 20% degradation, after this the degradation becomes more unpredictable and often the degradation curve dives.
The manufacturers spec’s the batteries down to 80% remaining capacity and the researchers mostly test to 80% remaining. In some tests they look at the degradation beyond 80%, and the conclusion in this research is that in general 80% is the end of life.
I just grabbed a picture from a cycle test, its clear that at 80% the curve dives:
Even if Tesla set the warranty at 70% this does not mean that the battery is very fresh at 72%. What it really means is that when you reach the 70% level, the battery has reached the end of life.
If you have lost 8% after 15 years, the battery has a lot more to give, but if you are closing in to 20%, it starts to be close to the end of life.
The two main parts degrading the battery is the SEI layer growing too thick and lithium plating.
If you have reduced these factors the life of the battery will be longer.
You do not need to worry if you can accept a higher degradation.
That statement is wrong, did you ever hear of the dunning-kruger effect?
It seems like as you continue to use statements like “SOC does not matter”, “these was not Tesla cells” etc but you have no source to back up your statements you are not interrested in learning or a discussion using facts or statements that can be supported by *anything* there we will not get anywhere With continuing this. Its better that you continue to charge to 80 or 90% or what you currently use.
For this thread and the original OP question, I would say that you should provide credible sources to statements you write.
It was not a part of the original OP question.
We have discussed that a lot in other threads. But that part is a very personal question, how important the power is to each owner.
To sum those discussions up:
So, After reading and understanding point 1, you can decide to charge to 90% every day if you are happy with loosing more capacity.
It doesnt matter if you just dont care or do it for the power you need.
There is one thing with power: Using high SOC often will increase the internal resistance more than it will with low SOC. This means, gradually loosing power, at least in an model 3 Performance where the battery set the maximum usable power most of the time.
My M3P that has been using low SOC will outperform a M3P 2021 (at the same SOC) that did use high SOC after a few years, as my battery will have less internal resistance and can deliver more power.
AAKEE,
Do we/you have data on Tesla's Charge Percent indicators? What of the actual battery energy percent do the indicate. I dont imagine those numbers are true/pure.
IE the car may say 100% but that may in fact be 90% of what the actual maximum capacity would be. Tesla would be foolish to let us charge the battery to its full capacity no?
also I doubt 0% percent is that. Its some other arbitrary number that the engineers deemed worthy of use to prevent the fools (myself included) from driving the battery into oblivion. Your car may pull over for you at or near 0% but there may well be another 10-15 percent of energy left as a buffer to keep us from destroying the battery....like my kids(and I) often do to our Traxxas cars
Anyhow long story short, are you accounting for this when you bring up your stats? I assume it should not matter as your contention based on data, of course, is the lower the charge the better and the lower the temperature the better....
beatle
Active Member
I get it, but the horse named Degradation that OP rode in on was beaten to death a few pages ago. My point was there's more than one reason to charge up to 90%, and it's a fun one. There is more to life than battery life, and it's possible to have your cake and eat it too.
I noticed quite a difference in power at lower SoCs, especially on my P85DL. I stepped down to 73% as my max charge rate to reduce the post-charge coolant pump whine, but I missed the extra oomph. The difference in power at lower SoCs has become less obvious as cars have matured (the refresh cars are pretty good here), but it's still a thing. Best of all, this charging behavior is still harmless. When I sold my P85DL it still had more range than 85% of other P85Ds in the same mileage bracket on TeslaFi.
There's no well defined maximum capacity for Li-ion batteries. It's like the Space Shuttle engines: you can always push just a little bit more energy into a battery (at the cost of battery life and increased chances of failure), just like you can always push just a little bit more fuel and oxidizer into a rocket engine with similar consequences on engine life and possible failures. In fact the Space Shuttle Main Engines were typically run at 104.5% thrust when it was discovered that they could be run at that level without jeopardizing their lifespan or causing much increased chances of failure. But if NASA wanted to risk it, they could have tried to run them at 110% or 115% or 120%, etc. You just have to define 100% at some level but you can push these devices beyond 100% if you really don't care about lifespan or failures.
That said, the industry has pretty much standardized on 4.20V/cell being 100% for Li-ion batteries. This is what cell phones use. My PHEV actually uses 4.10V/cell as "100%" for battery lifespan reasons but on a Tesla my understanding is that 100% is actually a full 4.20V/cell.
There's something like a 4% buffer below 0%. But 100% is pretty much the same as what cell phone batteries charge to.
Tesla charge to 4.20V/cell, thats 100% and the same as the branch standard.
100% displayed = 100% ”True SOC”
Tesla use a 4.5% buffer, so there is 4.5% true SOC at 0% displayed.
With Scan My Tesla we can se the true SOC number also (think it’s called SOC Min).
The true SOC is [displayed SOC+(100-displayed SOC)x0.045]
At 50% displayed SOC the True SOC is 52.25%.
Its so small differences so it does not matter in the big pitcure.
For the charging advice to have the car parked at 55% (for NCA) or lower most of the time to reduce calendar aging, the True Soc is accounted for.
The central graphite peak in the middle of the lower picture is at about 58% for a new battery (it moves upwards to above 60% after one year).
55% displayed SOC is 57% true SOC, so below the point for the central graphite peak.
Your point is valid but it will be a matter of personal choice, not facts or data we can look up. Its possible that we never will come to a joint way of seeing that.
Trying to change the opinion on someone else, like changing the political point of view…
Theres nothing wrong in charging to 90% for the ‘need for speed’ but it is a said thing being fooled by myths, charging to 80 or 90% for years, then finding that the battery degraded more than you thought it would, and then learning that 80-90% was about the worst SOC to have the char standing at.
I like power, but still I would like to keep the degradation down. If I loose more than 15%, it would need reduced speed (or drive another way for charging) to have enough range to drive to my work the coldest days.
Same for driving to my mother in law, but there is no SuC on the normal shortest way so a charge stop would cost like 1.5 hour of extra driving/charging.
Its possible to eat the cake and have it too, by charging higher but drive the car down to below the “step” in the calendar aging curve before it is parked, the calendar aging incease will be very small (negligible).
I have done this several times, still low degradation.
Monday night, charging full for driving 250km in -22 to -27C.
Seeing 495km (from 507km new) feels good also
beatle
Active Member
I'm not trying to change anyone's opinion, just offering the additional fact that the SoC affects more than just how far you can drive.
Again, after charging to 90% for over 3 years as the car's second owner, my 2015's battery was still in the top 20% for degradation.
I dare say that a future option for batteries will be the ability to remove them from the car into a Powerwall. (We already know that moving into utilities is expected to be an option).
So instead of just paying for a new battery, you get a Powerwall out of it, even degraded capacity is not a catastrophic event.
Sure, I can and will accept degradation. But as time rolls on and degradation actually starts to be a thing, it may not be as big of a thing as people try to make of it today.
I will keep charging mine per official instruction manual, designed for every day users/drivers and report back. as time allows. I am of the group that does not really care if my degradation is a little off one way or the other but curious about the topic, so I do appreciate the various inputs here. I've come to terms that I can focus better on my job if my car is charged properly. The extra money I can make focusing on my job offsets the financial losses from battery degradation . but each to his/her own of course.
One question, is for whomever but I have a feeling AAKEE is the one with answers. What is the best app to check out tesla battery and on the same topic to use car in general on apple watch etc.(Other than tesla app). Does the battery app. need an electric device plugged into tesla to work/transmit to/from?
. but each to his/her own of course.One question, is for whomever but I have a feeling AAKEE is the one with answers
. What is the best app to check out tesla battery and on the same topic to use car in general on apple watch etc.(Other than tesla app). Does the battery app. need an electric device plugged into tesla to work/transmit to/from?@beatle, I thought exactly like you for the first year of ownership and would charge to 90% for performance. After going through one winter where it's the cold that sapped my performance whatever the SOC, as well as after reading all this material on degradation, I ended up using 55% as day to day. I don't feel a big loss of performance but there is one. I realized that even with less power, my AWD+Boost was always in front of everyone in stoplight racing... Someone did dyno runs of a model 3 at various SOCs so I know what I'm losing and it's not that huge. Down low it's really significant though. As you approach 10% it's dramatic.
EDIT: At -20C it's also dramatic
Someone did dyno runs of a model 3 at various SOCs so I know what I'm losing and it's not that huge. Down low it's really significant though. As you approach 10% it's dramatic.EDIT: At -20C it's also dramatic
Why cant individual cells be changed if they fail early etc. It would be nice to have that option. Have a cell pop out and drop into a "Coin" box as Dead. Put in a new one.... I guess they all call it quits at the same slow rate? But I did have a bad (d) LiFe cell in one of my "toys" an electric scooter and after changing it worked like a charm.
Oh I know it is but perhaps in future designs to maximize battery and reduce waste...or perhaps for systems that are no longer under a few tons of car steel
and in a house system. Thinking more like the MATRIX. a little gizmo plucks out the bad cells and drops them. The best app would be a matter of personal choice.
To check the battery with real values, Scan My Tesla is ”best”. It need a hardware connection in the car but you get real values directly from the BMS.
Teslafi, tessie etc use ”over the air data” which is not complete, so they approximate a little. Like using the current reported range and divide by SOC, to calculate the maximum range. This gives small ertors and teslafi often show a litlle shorter range than the real BMS value gives. Not important but still only a approximate value.
Tessie seems to use a random initial capacity value, it might possibly even be ”setable” by the user. The degradation value is all over the place, and the initial capacity is sometimes strange.
I do not have tessie but teslafi. There is logs online, easy accessible and a nice layout so I still use it despite having scan my tesla + teslalogger where much more data (actual BMS-data) is sent via a server to my home.
For apple watch, I do not know.
E90alex
Active Member
Looking at the 4680 structural pack as what the future holds for Tesla, they will be moving to an even less repairable battery. That pack is unable to be serviced without completely destroying it.Oh I know it is but perhaps in future designs to maximize battery and reduce waste...or perhaps for systems that are no longer under a few tons of car steel
What you’re describing is already being done on many older hybrids and EVs. People can swap out bad modules or cells to make a dead pack functional again.
Oh I know it is but perhaps in future designs to maximize battery and reduce waste...or perhaps for systems that are no longer under a few tons of car steel
Sure, you could do that, if there was a need, but there really isn't a need. While it is close to a possibility with the Model 3's battery pack, take a look at the Model Y's. People have to literally chip the batteries out of the pack.
beatle
Active Member
It'd be nice to get a comparison of all the performance cars across the years and the power available at different SoCs. Here's a table for a 2017 P100D. I wish it also showed 90%, but I'm betting it's around 570kw.@beatle, I thought exactly like you for the first year of ownership and would charge to 90% for performance. After going through one winter where it's the cold that sapped my performance whatever the SOC, as well as after reading all this material on degradation, I ended up using 55% as day to day. I don't feel a big loss of performance but there is one. I realized that even with less power, my AWD+Boost was always in front of everyone in stoplight racing...
EDIT: At -20C it's also dramatic
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