A couple of days ago I bought a replacement battery (“compatible”, not original) for my laptop because the original one died for good. It should be a 2600mAh battery but Linux is identifying it as a 2200mAh battery, or at least I think it is. This is what I did to read my battery:

$ cat /sys/class/power_supply/BAT0/charge_full
2176000

$ upower -d
Device: /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               Hewlett-Packard
  model:                Primary
  power supply:         yes
  updated:              Fri 30 Jun 2023 12:01:32 PM CEST (97 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               fully-charged
    warning-level:       none
    energy:              32.2048 Wh
    energy-empty:        0 Wh
    energy-full:         32.2048 Wh
    energy-full-design:  32.2048 Wh
    energy-rate:         1.3912 W
    voltage:             16.505 V
    percentage:          100%
    capacity:            100%
    technology:          lithium-ion
    icon-name:          'battery-full-charged-symbolic'

According to customer support the battery is fine because those are only software readings, read from the chip on the battery, and is probably a BIOS/ACPI problem (which could well be, since it reports 16.5V instead of the nominal value of 14.8V). Anyone else has experience with something like this? Are there other more precise ways of reading the battery, other than what I’ve tried already?