I'm not sure the charge controller can actually charge individual strings. Sure there are voltage readings from 96 wires but you can't charge through those.
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Wiki Sudden Loss Of Range With 2019.16.x Software
- Thread starter Dutchmeeuw
- Start date
I'm not sure the charge controller can actually charge individual strings. Sure there are voltage readings from 96 wires but you can't charge through those.
I’d posit that it’s an all-or-nothing deal. They can’t restrict the max voltage on some modules or groups of cells because that would cause the pack to be grossly unbalanced.
In my recent reading on lithium plating, there was some discussion that it could be partially reversible. Tesla has mentioned that, in time, some affected owners may see a partial restoration of the lost range.
I presume their new detection algorithm will continue to monitor and adjust maximum voltage level based on measured lithium plating. The new thermal management strategy should minimize or prevent additional lithium plating, so here’s hoping we see improvements going forward.
If that's would they said then I would have said this in response:
Tesla is claiming this is degradation. It's not degradation. It's a dangerous condition that could cause a fire and they are crippling the battery intentionally to try and prevent the possibility of fire....in a SMALL number of batteries.
The difference is that "normal degradation" will result in less range when you charge the battery to full vs a dangerous fault in the battery could cause a fire if you charge to full.
Of course Tesla hasn't said any of this.
To some degree but comparing similar SOC charge/discharge ranges in strict watt hours still gives the lifetime advantage to the pure carbon anode.
Subtle added information. If you do get a little lithium plating, and you immediately discharge the battery, most of it should reverse.
Why is lithium plating irreversible in Li-ion cells?
Lithium plating has to react to form a solid electrolyte interphase layer or form dendrites or undergo some additional chemical reactions before it becomes "irreversible".
However, the dendrites do form, over time, in all of the graphite-only anodes; we know that. However, the rate of formation seems to be usage-dependent.
We already know that substantial lithium plating should only be happening with (a) fast charging at (b) low battery temperatures and is more likely to happen at (c) high states of charge. And it should discharge if you drive off immediately after charging.
Thinking about it, I don't think I've ever Supercharged with a cold battery. Always drove far enough for the battery to be heated and the regen/power limitations to disappear before reaching a Supercharger.
(Also probably never charged cold at all, now that I think about it. I don't use timed charging, so I start charging when I get home with a warm battery.)
Why is lithium plating irreversible in Li-ion cells?
Lithium plating has to react to form a solid electrolyte interphase layer or form dendrites or undergo some additional chemical reactions before it becomes "irreversible".
However, the dendrites do form, over time, in all of the graphite-only anodes; we know that. However, the rate of formation seems to be usage-dependent.
We already know that substantial lithium plating should only be happening with (a) fast charging at (b) low battery temperatures and is more likely to happen at (c) high states of charge. And it should discharge if you drive off immediately after charging.
Thinking about it, I don't think I've ever Supercharged with a cold battery. Always drove far enough for the battery to be heated and the regen/power limitations to disappear before reaching a Supercharger.
(Also probably never charged cold at all, now that I think about it. I don't use timed charging, so I start charging when I get home with a warm battery.)
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Unfortunately you're right. Other companies have not been learning the lessons which Tesla already learned. :-(
NIO recalls nearly 5,000 electric SUVs after battery fires in China
OK, if you have no cold weather, never charge to 100%, rarely use Superchargers, and have low miles, and *your* pack is showing sudden degradation, then there is probably something else going on with your pack.
All of the modules are wired in series, so you can't limit a single module. The pack is only as "strong" as the weakest module.
Circa late-2015 or 2016. Not sure exactly when.
Gone? No. It's a potential issue in ALL lithium-ion cells, no exceptions. It's just substantially LESS likely with the silicon-doped anode.
Yes. It's just less likely.
Apparently Li plating is basically caused by the pressure of charging exceeding the ability of the graphite to absorb the lithium, and it becomes a permanent problem if the metal lithium then reacts to form another compound which doesn't free up the lithium easily. It basically could happen to some of your battery at any time depending on local chemistry conditions at that exact point in that exact layer of the cell. More plating is worse.
You probably wouldn't notice teeny tiny amounts of plating in only a few cells.But various conditions make it more likely and more common. First and foremost is faster charging (more "pressure'). Second is high states of charge, because graphite which is "already full of lithium" has more resistance to absorbing more lithium. Third is cold temperatures in the battery, because they reduce the ability of the graphite to absorb the lithium. Finally, if you discharge immediately after charging to full, the metal lithium is likely to "unplate" before it reacts with the rest of the battery.
So yes, you are best off:
-- charging only to 85% ever
-- charging as slowly as you can get away with
-- keeping the battery on the warmer side (above 50F apparently) all the time
-- always driving and running the battery down immediately after charging
Obviously this is overkill! If you fast charge sometimes, charge to 100% sometimes, leave the battery at a high SoC occasionally, and do so with the battery is cold occasionally, you'll probably develop a little plating but it's likely to not be enough to worry about.
If you start with a cold-soaked car in below freezing weather, drive it less than a mile to the Supercharger, fast-charge it at top speed to 100%, and then park it for a few hours, you're probably maximizing your potential lithium plating problems. This is as I understand it anyway.
Limiting the SOC range to the "middle of the range" *definitely* helps with almost *every* form of degradation.
Circa late-2015 or 2016. Not sure exactly when.
Gone? No. It's a potential issue in ALL lithium-ion cells, no exceptions. It's just substantially LESS likely with the silicon-doped anode.
Yes. It's just less likely.
Apparently Li plating is basically caused by the pressure of charging exceeding the ability of the graphite to absorb the lithium, and it becomes a permanent problem if the metal lithium then reacts to form another compound which doesn't free up the lithium easily. It basically could happen to some of your battery at any time depending on local chemistry conditions at that exact point in that exact layer of the cell. More plating is worse.
But various conditions make it more likely and more common. First and foremost is faster charging (more "pressure'). Second is high states of charge, because graphite which is "already full of lithium" has more resistance to absorbing more lithium. Third is cold temperatures in the battery, because they reduce the ability of the graphite to absorb the lithium. Finally, if you discharge immediately after charging to full, the metal lithium is likely to "unplate" before it reacts with the rest of the battery.
So yes, you are best off:
-- charging only to 85% ever
-- charging as slowly as you can get away with
-- keeping the battery on the warmer side (above 50F apparently) all the time
-- always driving and running the battery down immediately after charging
Obviously this is overkill! If you fast charge sometimes, charge to 100% sometimes, leave the battery at a high SoC occasionally, and do so with the battery is cold occasionally, you'll probably develop a little plating but it's likely to not be enough to worry about.
If you start with a cold-soaked car in below freezing weather, drive it less than a mile to the Supercharger, fast-charge it at top speed to 100%, and then park it for a few hours, you're probably maximizing your potential lithium plating problems. This is as I understand it anyway.
For years we've seen stories of cold soaked cars at superchargers unable to even begin to charge because the battery was so cold until the battery heater kicked in enough to allow more charge...and stories of failed battery heaters resulting in 1 kw charging speeds (essentially nothing) for 10+ hours until the the BMS decided it was warm enough to charge faster.
How could these conditions have ever existed when the BMS was already programmed to not charge in these conditions?
Also, there is at least one confirmed case here where a cars range was significantly reduced and their peak power before the update was 450KW (close to the 456KW it was when new). Li plating causes significant increase in IR which results in significant power loss even if it doesn't result in range loss. How do you reconcile those facts with the theory that Tesla is accounting for Li plating now?
Well, it was fun trying to work out what was going on, but I have to say, the bottom line is:
--- Tesla is not communicating appropriately. We shouldn't have to be doing detective work to try to figure out what's happening.
--- Tesla is not communicating appropriately. We shouldn't have to be doing detective work to try to figure out what's happening.
Low temperatures in this case are below 50 degrees F.
I would agree that something has gone wrong if you meet those conditions and that pack might actually be eligible for warranty replacement, however getting Tesla to listen that request is going to be difficult right now.
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St Charles
Tesla, not TSLA!
I've never felt more vindicated for overthinking my charging behaviors:
Home charging:
1. Don't charge above 80% unless necessary
2. Plan to use the car shortly after charging
3. Never allow the car to sit with SOC over 70%
Perhaps I should rename my car to Mogwai
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If I'm Tesla and know these batteries are faulty and may cause fire, I'm obligated to recall and replace them. Cost-wise, it should not be every older battery still under warranty because of what Tesla has been quoted per this article:
"it resulted in a range loss for only a small percentage of owners.”
In the past they're repaired your existing pack when there were problems. They simply need to continue doing what they've always done when there are hardware faults within the battery pack. What they should never do is steal tens of thousands of dollars or allow fire hazards to remain in circulation.
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