On 3/8/21, Subhaditya Nath <[email protected]> wrote:
> I have a Thinkpad E495 that has Battery Charge threshold support. i.e.
> it can be set such that the battery starts charging at a specified
> amount of charge (say, 70%) and automatically stops charging at a
> specified charge (say, 80%). This feature is also available on Linux by
> using TLP (made by linrunner, his website is linrunner.de)
I just investigated a little more about it, and what do I see? Surprise!
It's just a shell script! Yeah! And how does it do the threshold thing?
Simple! It just writes the required values to -
/sys/class/power_supply/BAT0/charge_start_threshold
/sys/class/power_supply/BAT0/charge_stop_threshold
Done!
And the actual work is done by something called the 'natacpi framework',
which is implemented by the linux kernel itself. I don't know :shrug:
(I just gathered the above sentence after a few minutes of googling. I
know very little about the kernel and all)
For those who are curious, below is the output of `tlp-stat -b`.
Note this line -
natacpi = active (data, thresholds)
--- TLP 1.3.1 --------------------------------------------
+++ Battery Features: Charge Thresholds and Recalibrate
natacpi = active (data, thresholds)
tpacpi-bat = active (recalibrate)
tp-smapi = inactive (ThinkPad not supported)
+++ ThinkPad Battery Status: BAT0 (Main / Internal)
/sys/class/power_supply/BAT0/manufacturer = SMP
/sys/class/power_supply/BAT0/model_name = 01AV446
/sys/class/power_supply/BAT0/cycle_count = 205
/sys/class/power_supply/BAT0/energy_full_design = 45280 [mWh]
/sys/class/power_supply/BAT0/energy_full = 42750 [mWh]
/sys/class/power_supply/BAT0/energy_now = 26430 [mWh]
/sys/class/power_supply/BAT0/power_now = 6810 [mW]
/sys/class/power_supply/BAT0/status = Discharging
/sys/class/power_supply/BAT0/charge_start_threshold = 75 [%]
/sys/class/power_supply/BAT0/charge_stop_threshold = 80 [%]
tpacpi-bat.BAT0.forceDischarge = 0
Charge = 61.8 [%]
Capacity = 94.4 [%]
