The video was mainly enlightening about the mechanisms of degradation but it seems to support your conclusions generally (he says to store below 30, and you say to store below 55 which are both technically correct I think). I find it interesting that your figure show that very low state of charge being ok. It’s actually really good to know that if I arrive home at 10% charge and don’t feel like charging before I go to bed there’s no harm done (I do have a charger in my garage but its a very slow shared community charger which is often busy and so its not always convenient to charge immediately after arriving home). That part is very interesting and useful and I think different from what was presented in the video.Except that isn’t correct. Did you not read posts 15 and 17. To be precise, if you have a NCA battery, it’s best to be below 55% SOC as long as possible. Please look at the charts in post 15 and note the plateau at 55%.
From all this, it seems that storing at somewhere around 50% seems like a good compromise between less degradation than storing at a higher charge, while also leading to lower depth of charing cycle compared to always storing my car at 5% and then needing to charge it up to 90% before a long trip. So seems like I’m in good shape.
There will obviously be some times when I don’t store it below 55%. For example right now it’s at 75% because I had a chance to charge for free and I am not going on a long drive until Saturday. I assume that’s ok for a few days here and there, just not for the majority of the life of the car.