Candleflame
Active Member
yes, you are in oslo so you have degradation protection on your car though less range overall compared to i.e. someone living in south USA/Africa/Australia as we need less electricity to heat.
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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
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yes, you are in oslo so you have degradation protection on your car though less range overall compared to i.e. someone living in south USA/Africa/Australia as we need less electricity to heat.
After 8 months I have had 6% loss of range. I am at elevation and as of today we are starting to drive on snow floor. I think you are spot on. We will lose short term range due to temp and traction, but maintain battery capacity longer due to the average colder temps. Most of our loss is probably calendar loss added to summer temps, but not as bad as if we were in a different, warmer climate.
As I expected. Chemistry is harder than Elon thought, and Panasonic is better than he thought, beating or equalling them isn't easy. Semi needs max range, and Panasonic's NCA is better than the NMC that Tesla is doing with their 4680s and dry process. Panasonic is moving to 4680 form factor too (new factories in Midwest, OK or KS) but with their own process.
It was easy to compete against legacy automotive OEMs, just as SpaceX found it easy to compete against very legacy rocket makers in a cartel. Not always the case that the competition is asleep.
Except scientific 55% isn't Tesla displayed 55% because of the lower buffer (i.e. the Teslas can go a bit below zero).You can get away with 55% says the data
I suspect displayed 50% is more like 54% scientific.
bkp_duke
Well-Known Member
Not really. They can do the chemistry, that they have proven internally. Mass production scaling is the actual issue. Their equipment manufacturer for the 4680 line (by rumor) could not make the machines durable enough per Tesla's specs for high enough throughput. So, in typical Elon fashion, they fired them and are building their own machines.
The teardowns and analyses we have to date on the 4680s put them exactly where Tesla said they would be on their first-gen 4680 cells back in Battery day. There are two more iterations planned for the 4680s (at least), to incorporate additional changes (again, as planned) to the cell chemistry, both of which will increase energy density.
See videos on Youtube by The Limiting Factor, where they took a Jan 2022 Kato Rd cell (not a Giga TX cell - they have one of those now that is going through chemical analysis):
You also give Panasonic too much credit - they have near zero experience with Dry Battery Electrode batteries, as all their 2170 lines are optimized for the wet process (which takes about 10X the floor space of DBE). Because the 2170 process is a very mature process, they have over time incorporated things like graphite, etc. in to the electrodes which has improved energy density. These advancements were stepwise, and were not in place with the initial 2170 cells.
Again - the 4680 Tesla cells are going to be an evolving product, just like Panasonic's 2170s were. They will be substantially more energy dense in 2 years than they are now, again, just like the 2170s from 2020 are more energy dense than those from 2018.
The 4.5% buffer is ”spread” trough the whole range 0-100% on the screen. Of course it is in the bottom below 0% displayed but each percent on the screen is 0.955% of the total capacity.
True SOC is: [ 4.5 + 0.955 x Displayed SOC].
50% displayed SOC is about 52.25% true SOC.
55% displayed is 57.025% (lets call that 57%).
Even if these pictures of calendar aging show a straight line of increasing calendar aging between 55-60%, there was no tests performed between 55 and 60%.
The reason for the steep increase in calendar aging is the central graphite peak, it is located at about 57-58% when the battery is new, and moves a bit further up after some time.
55% displayed SOC (57% true SOC) is ~ the limit where the the calendar aging still is on the low side.
So we can possibly consider 55% displayed SOC the sweet spot between low calendar sging and maximized range.
Using a lower charge limit is not bad at all (better) but 50% is the lowest possible to set.
The key to really low calendar aging is to charge shortly before the drive, and not to use higher chsrging level than needed for the trip.
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Excellent! Where did you figure that out or learn it? That's the main mystery I had.
AlanSubie4Life
Efficiency Obsessed Member
It’s been explained here a few times, though the formula isn't provided too often. While all of the buffer is below 0%, of course, people sometimes get the math wrong and think they should just add 4.5% to their current SOC to get true SOC. But that's just not correct and the error gets larger, the higher the SOC.
(You can tell it's wrong because if you add 4.5% to 100% you get 104.5%, which is wrong of course. Always good to check limit behavior with formulas.)
The 4.5% is for Model 3 and Model Y (other vehicles have had different buffer sizes, and LFP Model 3 can have a dynamic buffer in some circumstances). It's just the well established buffer % corroborated by SMT.
As @AlanSubie4Life says, plus looking into the Scan My Tesla numbers. Very easy to verify.
True SOC in the picture below by the remaining/ nominal full pack = 47.8/81.2 = 58.86%
True SOC with [ 4.5 + 0.955 Displayed SOC] = 58.84%
(Scan my tesla SOC only provides one digit so the delta we see 0.02% lies within that)
I havent gotten .36 yet but did read some post(s) about that new function.
If you see a ”strange SOC”, this post might help a little, (or maybe increase the confusion
) :Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
When you do get 2022.36 let us know because there is something I don’t understand…in the new battery health function in the service mode..it says press the indicator stalk and the brake pedal and the key at the same time…what is the ‘key’ ?I havent gotten .36 yet but did read some post(s) about that new function.
If you see a ”strange SOC”, this post might help a little, (or maybe increase the confusion
Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
I can check a little when I get it.
Do you need to do anything special to enter ”service mode” ?
I do not feel the need to do any battery testing, currently I’m quite sure about my batterys status and capacity (slightly better than the NFP, I’d say). But I perhaps can look a little.
So I just did this (to a point). Pressing the indicator stalk and brake is easy. The key apparently just means you need to have a key, either phone or card, in the vehicle.
This then popped up. I didn't want to have my car off line for 24 hours so I didn't pursue it.
Sounds like the car battery must be cycled one time. I'd do this only if absolutely necessary, and in particular if you're at very low SOC. It's going to discharge to low single digits, then charge up to 100% or something. I would guess less than 24hrs, but who knows until someone does it.
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