Where did you see a recommendation to routinely charge to 100%? My car explicitly warns me not to charge above 90% unless necessary, b/c it will reduce overall battery life. It is also advised not to run the car below 10% charge. Both of these are known to reduce the life of lithium batteries.

Anyway, I’m not quite sure I follow how you are assessing capacity. I assess it with the range estimate at the top of the display (the small battery icon). When my car was new, my rated range was 313 rated miles at 100%. Since I only charge to 90%, my baseline is 280 rated mi @ 90%. I’m at 18k miles on the odometer in 14 months now and my 90% rated range estimate is 265 mi, so I’ve lost 5.5%.

Earlier on, I appeared to be having more significant range losses – my 90% range was down to 252 rated miles, an apparent loss of 9%. I learned a trick from Tesla that fixes this.

Half of that range loss was an illusion. I was typically plugging my car in when my battery was at 50-70% charge state. The trick is to frequently wait until you are below 40% charge state before plugging back in. It was a slow recovery, but I got 12 miles/5% of estimated battery capacity back over the course of 1.5 months, by doing this regularly. Each individual charge only brought back 1-3 miles worth of estimate, but it rose steadily until my 100% range estimate got up to 296 miles. Then it flattened. Now I make sure that about 1 in 4 charges starts at below 40% charge. That seems to be keeping the battery capacity estimate stable.