I bought a bunch of LFP cells a couple years ago to do an EV conversion of a Mazda RX-8. After a couple years of literally just sitting there, they went from a

I bought a bunch of LFP cells a couple years ago to do an EV conversion of a Mazda RX-8. After a couple years of literally just sitting there, they went from about 3.2 volts to about 3.1 volts. Tesla cell chemistry is different (unless you get one of the new ones that use LFPs from CATL), but it's not an inherent problem with electric cars generally.