There was an interesting chart posted a little while back (I think it was re Tesla but would apply to every EV using lithium ion). Charging from 0 to 100% of battery it lasted 500 charge (a year and a half?) while one of the other options was charging 30% to 70% was something like 40,000 charges. The less of the top and bottom you use, the longer the battery lasts, just not into infinity and beyond.