Your pack is probably in the top 1% of performance, or even better.
That is one of the big mysteries, why some packs perform so much better than others over time.
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Wiki Sudden Loss Of Range With 2019.16.x Software
- Thread starter Dutchmeeuw
- Start date
That is one of the big mysteries, why some packs perform so much better than others over time.
For me, it's perfectly acceptable as it's in line with where my pack was so it meets my expectations of what the warranty would cover and what I would deem equitable. If I were you I would expect a replacement pack in line with your pack's characteristics.
Actually, if my pack were replaced it wouldn't be with a Ludicrous upgraded 85. Tesla has been replacing those with 90DLs for several years now.
How unpleasant it is to read above, I agree. There is little doubt that Super Charging is extremely challenging for the 18650 NCA cells, which are High Energy cells with thick and less porous layers as opposed to High Power cells with super open and thin layer of materials.
This thorough German paper from Peter Keil describes ways to ensure BEV Battery life of at least 1000 Equivalent Full Cycles. It even has a section on degradation (dominated by lithium plating) when solely doing Super Charging.
https://mediatum.ub.tum.de/doc/1355829/file.pdf
Super Charging is NOT one of the means to reach 1000 EFC:-( In fact SUC simulation tests were stopped after just 120 EFC when degradation reached almost 25% (Pages 98-101)
Because of the severe degradation rate, the test were repeated with a reduced boost protocol and as well with a maximum cell voltage off 4,1V. The paper reports, even with reduced boot protocol - a capacity fade of 20% already after about 300 cycles from 3.2 V to 4.2 V or 700 cycles from 3.2 V to 4.1 V.
300 EFC is less than 350 km x 300 EFC = 105.000km == 62.000 miles.
In this light, Tesla 'COULD' decide to take the approach, that Tesla Model S users, who dominantly DC/SuperCharge and regularly goes to 100%, need to be tought better practices. A warning early in the cars lifetime, about the likely effect of the usage would have been in place - after all Tesla modified the charge curve for S 90D dependent on charging history.
Testing the maximum Voltage achievable is largely an anti recovery test:-(
(Other papers (from Peter keil and others) documents various Capacity recovery mechanism's in Li-Ion cells. One is Lithium deposited in the Anode Overhang area, which CAN be recovered with long periods at low SoC, another is slow cycling to reduce lithium plating. A dV/dAh charging analysis can immediately show in-homogenous lithium distribution (dv/dAh peaks smeared out) which ask for rest and severely left moved anode peak, which argues plating. The Tesla BMS can perfectly well do dV/dAh analysis, but to my knowledge, Tesla can only measure voltage on each full string of 70+ parallel cells, which wipes out the peaks we want to find, so Tesla potentially has to decide strategy on other measures (such as DV versus AC charging ratio))
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Now that I have linked to Peters excellent paper, I would like to hint to page 125, which shows another way to reduce battery life time. (I think it is almost impossible with a Tesla (*))
Figure 86. shows capacity fade for various cycle depths of 20%, 41% and 61% at different max voltages of 3,7, 3,9 and 4,1V for temperatures 10C, 25C and 40C. Interesting is that if one cycles deep (41 or 61%) at very low temperatures, the cells fails at the regular capacity tests where the cells are charged to 4,2 V to determine capacity, although they did not fail cycling to 4.1V.(They fail around 400 and 600 EFC)
That would be another - less good argued - reason for capping to 4,1V
Luckily the graphs ALSO shows 'Anode Overhang Capacity recovery' in the 10C, 20% and 4,1V (red) curve, because the test was interrupted for a few months. My favorite paper on this is:
Investigation of capacity recovery during rest period at different states-ofcharge
after cycle life test for prismatic Li(Ni1/3Mn1/3Co1/3)O2-graphite cells
Meinert Lewerenza, Philipp Dechent, Dirk Uwe Sauer
But it is no longer public, so costs money to download. But their results are somewhat recapped here:
https://www.researchgate.net/public...ry_of_commercial_cells_after_cycle_life_tests
*)
(It is difficult to charge a Tesla WHILE keeping battery temperature as low as 10C, so above is unlikely to happen. Two winters ago I WAS however able to charge my Model S from a single Phase 230V outlet at -6Celsius and the battery did receive around 60% of the power going in, so it cannot have been heated a lot. Newer BMS software may block this, although it could be considered an emergency)
BigNick
Infamous Fat Sweaty Guy
I’m happy to know my pack has fewer than 8 EFC worth of SuC/DC charging. And half of that was after the “nerfed” SuC rates of 2019.20.x.
Maybe a big bold statement in the owner’s manual that home charger installation is highly recommended for battery life?
Possibly even raise the price of the cars by $500 and include an HPWC in the frunk with every new car purchase?
Or even requiring home charger installation as a prerequisite for the full 8-year term of the Battery pack warranty?
For not disclosing potential risks of constant fast charging, packs that have been compromised as a result should fall on Tesla, not the owner. Because Tesla stated early on “our BMS is so awesome if something goes wrong it is our fault” when obviously the BMS didn’t take as good care of the batteries as Tesla believed it would. Now that they (and we) know, it is time to publish an official “battery best practice” document included in the owner’s manual and possibly as an addendum to the Monroney.
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Good point! If the new 'nerfed' speed is similar to Peter keil's 'Reduced Boost Second SUC' protocol, you can now SUC double as much with the same degradation
I hope the German engineers are busy measuring recovery effect after super charging. Untill -hopefully that - here is a best case example!
(Copyright:
Investigation of capacity recovery during rest period at different states-ofcharge
after cycle life test for prismatic Li(Ni1/3Mn1/3Co1/3)O2-graphite cells
Meinert Lewerenza, Philipp Dechent, Dirk Uwe Sauer
)
Left half of the attached graph shows degradation in percentage when constantly cycling either 6% or 12% around 81% SoC, which is called P1.
After a 300 days capacity is down to 88% for 6% cycled and 85% for 12% cycled. Leaving the 12% cycled cell at 81%, it quickly recovers 2% and leaving it there for another 200 days cause no more recovery. But reducing State Of Charge to 9% (Called P5) it recovers 4% over a long period of time.
The 6% cycled cells is immediate reduced to P1==9% and recovers from 88% to 94% (or 6% point) in a few days, then slowly recover additional 2% over the next 200 days.
The paper is mostly an alert to other Battery Cell testers, to remember to include resting at low SoC in their measurements or they CAN produce dramatically wrong results.
But a Tesla owner can 'utilize' this and leave the car at lowest possible SoC when arriving home, instead of immediately topping it up high! (Everything below 50-55% is okay for rest, but lower is better)
(DISCLAIMER, the tested Cell in the show Graph is not 18650NCA, but the Lithium Plating and the Anode Overhang recovery is assumed universal for Li-Ion cells with anode overhang)
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So what is your understanding on how they Reman battery packs? Obviously they are not building new modules anymore.
The other obvious way was to do it with new 100kwh pack and take two modules out as someone got recently here.
tinm
2020 Model S LR+ Owner
I was supercharging yesterday in what I've come to call my chargegated car (2013 S85, 114900 miles, 221mi @ 90%, never get over 57kW at a supercharger anymore, usually it drops right into the 40s kW, and charging takes MUCH longer). At one point a 2016 Tesla P85 I think it was pulled in and the driver came over and we got to talking.
He mentioned that his car is seriously batterygated and has been capped (100% at like 216 or less--yikes) and I told him about my chargegated car and we commiserated about the state of Tesla, batteries, service, etc. He mentioned this forum which I occasionally up-periscope into to see what the latest updates are, only to slink away quickly lest I get too depressed. But last night I decided to do a more serious attempt at catching up, and for hours I read every post for like 40+ pages.
Big mistake, it kept me up most of the night. I must've dozed off around 2am but then woke up at 345am and a question suddenly occurred to me...
Anyone think it's possible that chargegate/batterygate is why JB Straubel is no longer with the company? Think of the timing. It would be just like Elon to show someone the door for this debacle. Not saying he was responsible for the problem, but maybe the CEO believes he was or should have been on top of it, and had to take the fall for it. It also helps explain why Tesla's PR completely clammed up since last summer and how so many reporters have had great difficulty communicating with the company since then (though it was never easy). It also would explain why Elon only does interviews anymore with superfans and "safe" questioners. It might even help explain the steady arrival and departure of general counsels at the company (what, 4 or 5 since fall 2018).
I never expected I would get to the point with my car that I have range anxiety again, or "charging dread" on trips, but I don't think I'll ever take my car out of state again--too risky. I'd like to trade the car in but I wonder how chargegate/batterygate is affecting used prices. I can only assume my car's value has plummeted since May 2019. Blue book value is crazy good (low $40s) but I don't believe that for one second. I figure what, $10k-15k?
He mentioned that his car is seriously batterygated and has been capped (100% at like 216 or less--yikes) and I told him about my chargegated car and we commiserated about the state of Tesla, batteries, service, etc. He mentioned this forum which I occasionally up-periscope into to see what the latest updates are, only to slink away quickly lest I get too depressed. But last night I decided to do a more serious attempt at catching up, and for hours I read every post for like 40+ pages.
Big mistake, it kept me up most of the night. I must've dozed off around 2am but then woke up at 345am and a question suddenly occurred to me...
Anyone think it's possible that chargegate/batterygate is why JB Straubel is no longer with the company? Think of the timing. It would be just like Elon to show someone the door for this debacle. Not saying he was responsible for the problem, but maybe the CEO believes he was or should have been on top of it, and had to take the fall for it. It also helps explain why Tesla's PR completely clammed up since last summer and how so many reporters have had great difficulty communicating with the company since then (though it was never easy). It also would explain why Elon only does interviews anymore with superfans and "safe" questioners. It might even help explain the steady arrival and departure of general counsels at the company (what, 4 or 5 since fall 2018).
I never expected I would get to the point with my car that I have range anxiety again, or "charging dread" on trips, but I don't think I'll ever take my car out of state again--too risky. I'd like to trade the car in but I wonder how chargegate/batterygate is affecting used prices. I can only assume my car's value has plummeted since May 2019. Blue book value is crazy good (low $40s) but I don't believe that for one second. I figure what, $10k-15k?
@jensk2
Very informative posts. Just FYI, Peter Keil's paper, among other informative papers/articles, is linked in the Post#1 wiki, under the heading:
BATTERY TECHNICAL LINKS
COMPILATION OF ARTICLES/PAPERS ON LI-ION BATTERIES
Your commentaries are definitely helpful to better understand the contents of these technical articles for most readers.
Very informative posts. Just FYI, Peter Keil's paper, among other informative papers/articles, is linked in the Post#1 wiki, under the heading:
BATTERY TECHNICAL LINKS
COMPILATION OF ARTICLES/PAPERS ON LI-ION BATTERIES
Your commentaries are definitely helpful to better understand the contents of these technical articles for most readers.
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He has moved from CTO, an executive role, to an advisory role as a senior adviser. Still with the company. May be he did not agree with the capping of the owners' batteries and look at their face and say it's all normal.
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Just to clarify, you mean mean high current vs low current charging. All charging is actually DC. It's just that an AC source goes through the on board charger to turn it into DC. I'm sure you already knew this though
Just hit 109K miles and 5 years. 1/3 of my driving has been long distance trips so all super charging. Of the other 2/3rds commuting (260 mile round trip) about 15% of that has been super charging. That means about 40% of all my miles have been supercharging yet my battery is still doing great.
Frequent supercharging is probably not bad for the battery (especially if you compare it to 80 amp wall charging). Why?
Does Repeated Supercharging Shorten Life of Battery Even at 90%?
Think of it in terms of what is flowing through the charge port. AC, which is rectified, filtered, and voltage/current regulated by the on-board charger (or 2, in some older cars), or DC, which is rectified, filtered, and voltage/current regulated by an expensive, large, heavy bank of off-board chargers.Just to clarify, you mean mean high current vs low current charging. All charging is actually DC. It's just that an AC source goes through the on board charger to turn it into DC. I'm sure you already knew this though
DC charging is always capable of delivering more power (50kW min DC, vs 22kW max for dual 80A chargers AC). That's the issue. The "all charging is DC" is really a pedantic distraction. It's the level of power being fed into the battery that's the (potential) issue. Like you, I've done a lot of DC charging (mostly SC, a little Chademo). My battery is still in great shape, despite a chargegate slowdown (SoC + kW ~= 110). I hit >100kW @ 17% for a bit after 150 miles of driving yesterday.
Is that option or fact? I had imagined building reman packs came down to assembling a new pack with relatively closely matched modules from old, dead packs.
I think those are two different things. I think Elon has general disillusionment with media (not unfounded) so is generally doing less of it. I think you could argue the JB thing either way: that he was being held accountable for charge-/battery- or that Elon is a tough guy to work for and he needed a break and with the Model 3 starting to ramp, his work was complete.
Ferrycraigs
Member
I have no idea how they remanufacture packs. But several times on here, including from Jason, we are advised that the chances of an odd Module fitting in with the rest of the pack, is less likely than winning the lottery. A great pity as it would be an easy, and acceptable, solution to many problems.
When I saw the new 14 Module, 350V 85 kWh Pack, my immediate thought was, they have gone to the trouble of designing and modifying this in order to address the current battery problems. But that could easily just be wishful thinking on my part. But having just spent the last few months reducing the Pack variations down to one variant, the 100 kWh Pack, I struggle to come up with a rational explanation why they would spend the time and money developing a new battery variant.
So where are they getting the used packs they call remanufactured? Its obvious they aren't combining the good parts from other bad packs. Is it from totalled cars that they insure themselves?
I am not sure we have established that. As @Ferrycraigs noted, you probably cannot just swap a group or module into an unhealthy pack, but I don't see why they cannot disassemble all the packs they get and then match groups or modules that have similar characteristics and then use the BMS SW to smooth out any minor unevenness.
This is a good statement of the nub of the (legal) issue. The BMS limits the battery in an endless variety of ways in response to the condition of the battery. And how it does so is further refined. Some batteries do well, like Sorka's battery despite high SC use. Some batteries might never see a SC but might be harmed by sitting at 100% SOC in the cold for just one night. The owner might not even recall the incident. Or again, just random wear.
I think it is perfectly appropriate for the BMS to constantly assess the condition and state and environment of the battery and respond accordingly to minimize the risk of battery failure and maximize battery longevity. I would expect nothing less. If a consequence is that some of the range is decreased, or the charge rate is slower, unless it violates a promise (now 70% for range loss) that isn't a violating of intended use, but simply a function of the battery aging and wearing and the BMS responding to that degraded battery condition.
No basis for this.
Exactly. reversible lithium plating. cool temps (~50 F) helps too.
The risk isn't that simple as Sorka's experience and many others illustrate. Makes me think it isn't just SCing that increases the risk, but something else. Perhaps sitting at high SOC for long periods. In either case it's due to use, and that isn't covered.
Still no answer to the question What do you think condition Z is? and how many people have > 30% loss?
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