Not really only a forum rumor. I've talked to a lot of people that deal with Lithium Ion batteries for drones and remote control cars and they all say the same thing, not to leave the battery at 100% unless it's going to be used right away and don't go lower than 10-20%. So I'm still kind of having issues believing none of that really matters. I'd think if it didn't effect the battery health all that much, it would be front page news from Tesla and every other EV manufacturer, as they wouldn't have to be concerned about a battery pack failure within the warranty, so they'd tell their customers to charge to whatever they want and not think about it.
Think I need to research this a bit more from many more reputable sources.
Yes it is forum rumors but not limited to this forum.
Did you read the link from Tesla about batteries?
I started with lithium battery powered remote controlled models 2006, still have a lot of them (drones, RC-helicopters etc.)
In general the usage differ, a lot.
Lithium batteries have higher internal resistance at SOC’s below 20%. This means they have to flight hard to deliver high power below 20%. An RC helicopter will have very high power demands an the battery will struggle to deliver the needed power ( >10C) below 20%. This cause excessive heat and wear on the battery.
Our Tesla is different and a normal drive is using about 0.25C or so (from full to empty in 4 hours). This do not put any strain on the battery.
All research show that this is safe and even cause less wear at low SOC.
If you try to overload the battery, the Tesla limits the power to safe levels for the battery.
For the 100% SOC “issue” I havent heard the same down to the our panic as in the Tesla communities.
All data I use comes from research reports.
It quite easy to see that the calendar aging do not increase extremely above 90%.
For normal temperatures 70-100% is about the same. Leaving the car at 100% cause about the same trouble as 80 or 90%.
This is cutouts from research reports:
Most research implies that in some cases 100% causing even less calendar aging than 80-90%:
What is really clear is that a day or two doesnt brake the battery.
High SOC cause the internal resistance to increase more, 100% cause slightly higher increase over a long period than 80%.
For a day or so, we can not measure the difference.