I remember recovering dead 18650 cells from laptop batteries and “restoring” them with a 12V modded PC PSU. Quite a few of them actually started working again and had some capacity for a few tens of additional cycles. Those cells were never left unattended in a charger and they were always only used in a device you could chuck in a moment’s notice.
10/10 do not recommend.
Tobberone@lemm.ee 4 hours ago
Well, there is some data/rumours out there, stemming from a Dutch Tesla forum, that suggests that some fast charging might be beneficial for battery longevity. This seems to corroborate that. I can’t remember the case for always fast charging, though.