Wrong "time-to-empty" for multiple battery laptop

[Joschi Brauchle]

Hello everyone,




The are two batteries installed in this machine:
mo-thinkpad01:~ # upower -i /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               SONY
  model:                45N1111
  serial:               12294
  power supply:         yes
  updated:              Fri 28 Feb 2014 09:37:25 AM CET (1202 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               fully-charged
    energy:              23.2 Wh
    energy-empty:        0 Wh
    energy-full:         23.2 Wh
    energy-full-design:  23.2 Wh
    energy-rate:         0 W
    voltage:             12.471 V
    percentage:          100%
    capacity:            100%
    technology:          lithium-polymer

mo-thinkpad01:~ # upower -i /org/freedesktop/UPower/devices/battery_BAT1
  native-path:          BAT1
  vendor:               LGC
  model:                45N1127
  serial:               4696
  power supply:         yes
  updated:              Fri 28 Feb 2014 09:57:25 AM CET (3 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               discharging
    energy:              22.94 Wh
    energy-empty:        0 Wh
    energy-full:         24.75 Wh
    energy-full-design:  23.48 Wh
    energy-rate:         2.239 W
    voltage:             12.51 V
    time to empty:       10.2 hours
    percentage:          92%
    capacity:            100%
    technology:          lithium-ion
  History (rate):
    1393577845  2.239   discharging
    1393577815  1.652   discharging
    1393577785  1.690   discharging
    1393577755  1.803   discharging










Is this a known limitation?



Best regards,
Joschi Brauchle
--
Dipl.-Ing. Joschi Brauchle, M.S.

Institute for Communications Engineering (LNT)
Technische Universitaet Muenchen (TUM)
80290 Munich, Germany

Tel (work): +49 89 289-23474
Fax (work): +49 89 289-23490
E-mail: joschi.brauc...@tum.de
Web: http://www.lnt.ei.tum.de/

I have the following problem with a Lenovo Thinkpad T440s laptop, but is looks like a much more general problem that affects may users (will provide bugzilla links later): As you can see, only BAT1 is being discharged, whereas BAT0 stays fully charged. Thus, the "time-to-empty" flag is only available for BAT1 and clearly only displays the time to empty FOR THAT PARTICULAR battery, but not when using ALL batteries. As a result, the current "time-to-empty" is basically a useless information for the user, as it ignores the second, fully charged and available battery. Imagine the case where BAT1 = 5% charged and discharging and BAT0 = 100% fully-charged. Then upower will display something like ~5 minutes remaining battery life (because it ignores BAT0), but in reality the total lifetime of BAT0+BAT1 would be multiple hours. I would like upower to provide an additional "overall-time-to-empty" value using ALL batteries / energy sources installed.

smime.p7s
Description: S/MIME Cryptographic Signature

_______________________________________________
devkit-devel mailing list
devkit-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/devkit-devel