I’m asking this question as I think it’s probably needed to prolong the laptop’s battery lifespan.
The laptop I’m using is already 3 years old and recently when I was upgrading stuffs I noticed the old battery has become badly swollen (it might have been swollen a long time ago just that I didn’t notice as I don’t open the laptop’s back cover too often), so I replaced it with another one.
But anyway, in order to further prolong the battery’s lifespan I’m considering about limiting the battery’s charge threshold, but this laptop is a bit different from others, that I couldn’t find the
/sys/class/power_supply/BAT0/charge_control_end_threshold file that’s supposed to exist since 5.4 kernel.
Though for this laptop the battery is less relevant (lasts only for about an hour or two, with CPU clocks throttled to around 540MHz), it’s still useful to keep data safe in case of a power outage (so I have enough time to conclude the work and shut down, similar to a UPS).