You will get conflicting answers about this.
The main reason is that there are a lot of forum myths. A lot of people got cought by these myths.
For low SOC = the lower SOC the better, when we are talking degradation. Even down to 0% if we only think about the lithium cells.
If the Hv Battery goes too low it shut down to protect itself, and then the 12V battery is mot charged. Most Teslas have a lead scud battery that does not like to be discharged.
So, keeping low SOC but not below 0% displayed (to safeguard the 12V battery) is safe.
This is a calendar aging curve from actual testing. Most teslas have the NCA chemistry, all LR and Performance have in USA.
View attachment 903681
(This is one chart but the research comes up with the same result each time. This is valid data.)
We can clearly see that low SOC is causing less degradation from time.
High SOC cause more degradation but there is not a big difference between 65-100%, so leaving the car at 90% is “safe”.
It cause more degradation than if below 60% but about the same as most people charge to, 70-80%.
For Cyclic aging, low SOC is better and small cycles is better.
100% is worse but not a very big difference to 80 or 90%.
This chart shows NCA cells cycled to 0 % from 100%, about 90% and about 80%.
Normal driving /charging is at the same rate as the grey lines, sometimes hidden behind the blue line.
100-0% cycles did hold about 625 cycles before they lost 20%.
90-0% cycles did hold for 800 FCE (full cycles equivalent) before they lost 20%
80-0% did hold up 1000 FCE cycles before they lost 20%.
View attachment 903682
625 cycles is about 250.000 km or 155.000miles
800 cycles is 320.000 km or 200.000 miles
1000 cycles is about 400.000 km 250.000 miles.
As we see, going down to 0% does not kill the battery.
We also see that 100% will not kill the battery but it reduce the cycle life with about 40% compared to 80% cycles.