Battery capacity status reporting inaccurate on X1 Carbon 7 Gen

[amicose]

After almost 1500 charge cycles, both Windows and Linux tell me that my battery is still at approx. 99.98% original capacity. Here's the status report in Linux:

Code: Select all

$ upower -i /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               LGC
  model:                5B10W13930
  serial:               457
  power supply:         yes
  updated:              Tue 24 Oct 2023 13:35:02 CEST (7 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               charging
    warning-level:       none
    energy:              50.95 Wh
    energy-empty:        0 Wh
    energy-full:         50.99 Wh
    energy-full-design:  51 Wh
    energy-rate:         7.619 W
    voltage:             17.083 V
    charge-cycles:       1498
    time to full:        18 seconds
    percentage:          99%
    capacity:            99.9804%
    technology:          lithium-polymer
    icon-name:          'battery-full-charging-symbolic'
  History (rate):
    1698147302	7.619	charging
    1698147272	7.704	charging
    1698147242	7.805	charging
    1698147212	7.890	charging

This is after recalibrating this morning with tlp ($ sudo tlp recalibrate BAT0).

I'm no longer in the warranty period with this device. Anyone have any ideas what could be leading to the erroneous capacity measurement?

[dr_st]

Some batteries simply do not report capacity change - they always show as if current capacity = design capacity. I know this to be true for Sony batteries for Thinkpads of ~15 years ago. Have never seen it on an LGC battery, but things may have changed since I last looked.

[amicose]

If that's the case here, it would be interesting, as the "current capacity" has per all status reports been the same since I got the device, almost four years ago