Complete battery degradation reversal!

RIP_OPEC

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Joined
Jul 15, 2018
Messages
78
Location
Arizona
Tesla Owner
Model 3
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#1
I have nearly 5K miles on my Model 3 and my maximum charge decreased from 310 to 304 over several months. However, today I was able to charge all the way to 310 miles again. There was no significant difference in temperature as I always charge it in my garage. Perhaps the recent software update has allowed us to charge to higher extent than before? As I recall reading somewhere that charging to 100% is not really 100%, Tesla artificially caps the maximum charge level.

I am very surprised by regaining the full range, as I've been leaving it charged at 100% overnight daily and supercharging 2-3 times a week, and often leaving it out to bask in Arizona's 120 F weather.

Edit: Am on 32.2
 

FF35

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Jul 13, 2018
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337
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New Jersey
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Model 3
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#2
Don't worry. With the way you maintain the battery, soon enough you'll see a larger degradation than most Model 3 owners.
 

NR4P

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S.E. Florida
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#5
I have mine set to 90%. Sometimes its 280 miles, sometimes 277, 278, 279 or 280. I think it was 276 once.
I don't worry about a few miles as I suspect the charge cut off is by the HPWC/car communication, and when it cuts off (i.e. x hours before full I check the car), are just normal variations amounting to 1%.
 

Firewired

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Apr 9, 2016
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San Antonio
#6
I thought you were joking about the car ay you are treating your battery. I never charge to a 100% and leave it there. I only do 100% if I need to for trips and use it right away. Maintaining a battery at 100% especially when warm definitely leads to parasitic loss of battery capacity.

Jeff Dahn is one of the world’s experts on batteries and he has an interesting lecture explaining how to take car of lithium batteries. Dr. Dahn used to do research for 3M, but has since been recruited by Tesla.

().
 

RandyS

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Apr 6, 2016
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San Diego
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Model 3
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#7
I have a 5 year old Model S P85. When new it would charge up to 255 miles if/when I charged to 100%. That was usually when going on a trip and I would leave shortly after getting to 100%. Most of the time, I would operate the car around town in the 40-70% charge range.

After 5 years of driving, the car has 49,000 miles. I recently charged up to 100% prior to a longer day of driving and it went to 253.

However, is my assumption that in 5 years of driving the battery only "lost" 2 miles of range? No, not at all.

Tesla has made many adjustments to the software and instrumentation over the years. And while I din't know exactly what they have done, I do know that they have made adjustments. Are they letting me access more of the battery now than before? Not sure...But I take the 255/253 numbers with a grain of salt (meaning that they are real numbers indicating real driving range, but I don't think they're comparable because of the software updates)...

All I do know is that the car has plenty of range and I really enjoy driving it...
 

KarenRei

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Jul 27, 2017
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1,647
Location
Reykjavík
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#8
I thought you were joking about the car ay you are treating your battery. I never charge to a 100% and leave it there. I only do 100% if I need to for trips and use it right away. Maintaining a battery at 100% especially when warm definitely leads to parasitic loss of battery capacity.

Jeff Dahn is one of the world’s experts on batteries and he has an interesting lecture explaining how to take car of lithium batteries. Dr. Dahn used to do research for 3M, but has since been recruited by Tesla.

().

Great video, though a bit outdated. He downplayed the impact of swelling, but the higher the energy density of a cell, in general the more significant problems with swelling are.*** For the extreme end on the anodes, you can look at pure silicon anodes, which hold ten times as much lithium as pure graphite - but tend to suffer from severe degradation because they swell and contract so much that they rip themselves apart.

In general, swelling is pretty directly proportional to the amp hours of an electrode, because that's determined by how many lithium ions can be reversibly intercalated into the electrode, so if Ah/kg rises, so does Li*/kg.


*** Caveat: my background on this is mainly from reading research papers investigating new electrode techs, not the phase of bringing cells to the market. It's always possible that swelling is more of an issue at the research phase but generally resolved by the time it comes to bringing cells to market.
 
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