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Leaving the car at 0%
- Thread starter ngng
- Start date
No.
To start, cyclic aging is only a fraction of the annual degradation. Youre looking at 1% or below. For smaller cycles in medium low SOC perhaps 0.5% cyclic aging each year.
Next part, smaller cycles wear less even if we count per energy and not per daily charge cycle.
The term FCE means Full cycle Equivalent and means that 1 FCE in the graph equals one 100-0% cycle. So a 10% discharge cycle will need 10 actual cycles to count as 1 FCE.
Panasonic NCA close to Tesla cells, cycled from the voltage shown to 0% (2.5V)
As we can see, the lower the charging target the lower the cyclic aging.
100% = 4.2V then 10% lower SOC for each 0.1V, so 3.7V equals 50%.
The cycles are smaller but the battery holds up many more cycles.
4.2V to 0 lost 25% on 750 FCE = 750 actual cycles.
3.7 - 3.8V to 0% lost 10% in 1000FCE, as they are 50-0% two actual cycles needed to get 1 FCE so they was cycled 2000 times (to reach 1000 FCE) and lost 10%
Heres actual tesla model 3 cells taken from a 2018 model 3 and tested:
It is small 10% cycles to one FCE equals 10 actual charge/discharge cycles.
The sweet spot is 35-55% in this test.
They used quite high discharge and charge rate so if they had used power more comparable to how we drive, the lower than 35% might have looked different.
Anyway, lets use the worst case, 5-15%.
Lost about 10% for 500FCE.
A model 3 LR goes about 400km if we charge it full and drives until it stops, right?
Maybe longer but, at least 400km.
500 x 400 = 200.000km, for 10% loss.
Thats 1% for 20K km which is at least about average annual driving range.
This was the worst case, right?
If you do the same in the sweet spot you loose 5% for 1000 FCE, thats 1/4 of the numbers we just calculated.
So, you see that the region causing low calendar aging also actually cause low cyclic aging.
My M3P had 492 km range out of 507km on the last full charge before changing to a MSP. The other cars in teslafi was down to 460-465 km at the same ODO.
I did not have to trade calendar aging vs cyclic aging.
So my car had like 1/3 degradation compared to the other cars, still I had ~55 SuC chargings and 35 charges to 100% during my 2.5 years with that car.
Okay, plot twist! Just got an notification that the car was charged and is at 100%
They're determined to destroy that vehicle.
*NOW* the responsible thing for you to do is enable sentry and A/C to bring it back down to like 55%.
No, the 8 numbers of 50-60% charges will wear much less than the 10-90%. Much less.
Look at charts cycling cells graded in FCE.
We count cycles in FCE.
Cycles in general wear much less if they are small. They also wear much less if they are placed low, like 20-30% or so.
Heres a 0-90% cycle test. 30C at load 2C degraded 20% at 3000 cycles.
Same cell type. Lower part of the picture, cycled 40-50% at about the same temp, same load. Got down to 15% then flattens out. (They stopped the 28C? as the others was following closely, they often do like that when they se that they follow close and continuing with one wont add to the result.
Upper part of the pucture: Same temp/same load, but 10-20%. Very low degradation and then flattens, will go on forever….
Its of cours ok to do like that, but you are mot saving the battery from anything bad with that.
100% is not even close to as bad as the forum myth. 80-90% cause the about same degradation from time as 100%.
Theres no need to drive asap from 100%.
If you anyway have the car at 80-90%, you cause snout the same degradation from time anyway.
The battery will hold up good, but you will not have the lowest degradation.
As seen below, ~65-100% cause about the same degradation from time.
But charging to 100% every day would put the cycles high in the SOC region, invlcreasing the cyclic aging.
Um.They're determined to destroy that vehicle.
*NOW* the responsible thing for you to do is enable sentry and A/C to bring it back down to like 55%.
So, @ngng sold the car to, as in:
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ngng said:
I ask because I sold my X to Carvana and have been causing the SOC to decline by frequently waking the car up.
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So, this isn't @ngng's car any more. It belongs to Carvana.
I realize that Carvana is full of people who don't quite understand how Teslas work. But the responsible thing would have been to transfer ownership, including on-line ownership, to Carvana. Let's see.. As per https://www.tesla.com/support/how-add-or-remove-vehicles-tesla-app, which goes into some detail.
Once ownership has been transferred, the original owner won't have visibility on the car. Or, maybe what I should say here is, shouldn't have visibility on the car.
While it's entertaining for all of on this thread to hear about the foibles of this poor Model X sitting in a Used Car Parking Lot.. Something doesn't seem quite right. Did Carvana get actual ownership by both getting the Title signed over (bet they did) and getting the car transferred to Tesla App and Account in their name? If the latter wasn't done, exactly how is the eventual buyer of this car going to take electronic possession without having to go in circles?
Do you want the VIN so you can take care of this yourself? You're being very prescriptive with what should or shouldn't be done.
When I bought this car the account was tied to the original owner and transferring ownership was simple. I logged it to Tesla, uploaded my proof of ownership, and authz by changing my vehicle name.
They're determined to destroy that vehicle.
*NOW* the responsible thing for you to do is enable sentry and A/C to bring it back down to like 55%.
No idea what they're doing, but the doors, windows, and climate have all been on today. I'm curious what their copywriter is going to slap together when the ad goes up.
Nah, I'm not trying to be a heavy or something.
It's just that.. if I sold a car to somebody.. I'd make a point of Making Darn Sure That Whoever It Is Has Possession of The Car.
Like.. I wouldn't sign over the title, then throw the keys in a trashcan on my way out the door. That's not how I roll.
Now, a sane buyer would insist on being handed the keys. So.. how did the Carvana guys do it when the transfer actually happened? Right, bill of sale. Right, title gets signed over. Right, key cards get handed over. But did they ask about if there were cell phones being used as keys? Did they ask about the Tesla Account in any way? Or was it.. they didn't know about that stuff, didn't ask, and the seller walked away, snickering?
Feels like a security breach plus ignorance at Carvana. If it was me, I'd have sat down and explained it all to the buyer. Now, if at that point, the buyer blows you off, maybe you leave a note with something along the lines, "I offered to transfer official Tesla ownership of this car to you, and you refused to take possession.", with your signature.
So.. Come the day Carvana takes a check and hands the keys over to the New Owner, the New Owner is going to have some trouble. Not insurmountable, but said owner's going to have a week or three getting paperwork back and forth to Tesla before Tesla rips the car out of your account and puts it in the new owner's. So much for taking a 200 mile trip.
In terms of who gets blamed for all this.. the natural thought is that the newbie will blame the dealer. Or you, if they get on-line and figure it out, or call Tesla and ask.
And you did this to this person you don't even know because?
@ngng - the solution is simple. You know the car's location (in CarMax's lot). When you see the car at someone else's location, change the name of the car to something like "Call (888) 555-1212) for setup"... using your phone number.
Then when the new owner calls you, do the transfer dance. Really, that'll likely be easier for the new owner than dealing with CarMax, since they don't seem to be aware of how it works.
Then when the new owner calls you, do the transfer dance. Really, that'll likely be easier for the new owner than dealing with CarMax, since they don't seem to be aware of how it works.
Have you ever transferred ownership of a used car to your name? Yours posts indicate that you have not. I bought previous X from a dealership and did exactly what I outlined in my previous message. It took about 24 hours and is very clearly outlined when anybody adds a car to their Tesla account.
ucmndd
Well-Known Member
Your opinion here appears to be “be afraid and make people afraid because there could be consequences.”
If you want to maintain that approach for yourself, then by all means please do. But the data doesn’t support your fear and doesn’t support the idea of going around making people scared when they’re asking for facts and evidence.
shahryaran
Member
shahryaran
Member
Interestingly, cycle fast charging at lower temperature has greater capacity fade than calendar aging.
ucmndd
Well-Known Member
250kw into an ~80kwh Model 3/Y battery is just over 3C at peak (250/80 = 3.125).
No, it has not. That chart shows nothing about fast charging.
500FCE equals 200K km, we do not modt often not drive that during the ~three four years it takes to loose 10% on calendar aging.
To begin with, that chart does not show supercharging. The picture comes from This report, page 118.
700mA is 0.24C on this cell, which equals about 17-20kW on model 3/Y LR/P.
For this chart, it shows the cyclic aging when the cells are cycled at three different SOC regions, se pic further down.
We can learn that at low SOC, the cyclic aging is not very temperature dependent, but at higher SOC it is.
Tesla does only heat the battery to 5-10C when performing preconditioning for a drive, so we will not get the cells much higher than that expect for superchsrhing sessions (A late regular charging also heats the battery to 20-30C if max AC charge is used and the car is inside a garage)
Low, medium and high SOC regions, as usual we se on the picture above that the cyclic aging is much higher, near to the double at high SOC compared to low SOC.
For supercharging, constantly supercharging might break the battery later in the cars life, but it probably happen beyond or well beyond 200K km.
As it seems, it will not induce much capacity loss in the pack until some cells develope short circuits which renders fault codes.
The spec for loose cells is around ~2-2.5A charge (0.5C). But thats for CCCV charging without preheating/heating the cell and without a BMS managing the charging power vs SOC and cell temp.
Equals ~37-40kW for a model 3/Y LR/P.
The managable C-rating is temperature dependent, and I havent seen specs for charging curves that is temperature dependent but there sometime is for discharge.
Main issue with fast charging is lithium plating and the antidote for that is to have the cells heated to at least 40C (which Tesla does).
You might have seen the recent articles about some company having data that shows that fast charging does not degrade the batteries according to their data.
It looks like there is not much capacity loss measured by the BMS’es but lithium plating still occur and eventually after extensive fast charging the battery felelops short circuits.
I know about one M3P in Sweden that had ~56000 kWh fast charging, and very little AC charging. The battery broke due to some shorted cells. In my mind, from what I have learned, that most certainly was caused by the lithium plating.
The owner has Scan my Tesla and the Nominal Full Pack showed about 12% degradation just before the battery went bad (I think the car had ~230K km at that time).
The car was about 3-4 years at that time and many other low miles M3P at the same age showed about the same or only slightly less degradation.
For supercharging, expect to not see very much degradation from that, and if doing extensive supercharging expect the batteey to break without early signs of high degradation. When we get the first signs, the battery might already be on the trip south.
I supercharge happily everytime in need to, but I do not use it more than needed. I always preheat before supercharging.
As I have free SuC for three years I might do some longer trips which would include a lot of supercharging during a short period, but then the car will be doing mostly short trips and AC charging during the other times of the year. Low SOC and small cycles tend to recover some of the lithium plating according to the research.
If my BMS was correct about the capacity the nominal full pack/capacity dropped about 0.5-1kWh during the longer trips/several SuC (3-4K km trips) I had with my M3P I had. During the month after these trips the nominal full psvk recovered completely. I saw the same behavior both summers, so it is probable that it was degradation from supercharging that took the 0.5-1kWh and it was recovered lithium plating that got the capacity back.
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