Yeah Lithium batteries stay healthy for much longer if you keep them roughly between 20%-80% charge. Many laptops and phones now use similar management strategies to avoid wearing out the battery.

That’s common for lots of batteries. My laptop has a setting to not charge between 50-70% because it lives on a dock and doesn’t need max life in travel. Batteries are stored between 40 and 80% usually. So it makes sense that a car with the same battery chemistry recommends the same thing. It’s only different in regards to a car being important in an emergency, but realistically, an emergency is unlikely to be both sudden and require long distance driving. So 100 miles of range is probably as good as 400 in common usage.

Your phone does the same thing just without communicating it. Samsung phones let you change the percentage of the battery is “100%” charged.

As mentioned, lithium batteries are happiest charged around 20-80%. No shame in going higher if you need it, but typical day to day I drive less than 50 miles in a day. If I’m using 20% of my battery capacity, I don’t care if that means I go from 100% down to 80% or 80% down to 60%. I’ll plug it in at the end of the day and charge back up to whatever I want by the next morning.

Put another way, how many times have you woken up thinking you need to stop at a gas station because you only have 3/4 of a tank?

It’s not just Tesla, that’s just general good practice for lithium batteries in general. Including your phone, laptop, Bluetooth devices, power tools etc. etc.