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On my thinkpad t440s I ran ubuntu 14.04 happily for around 2 years, in the beginning having a battery life of over 7 hours, and still now easily 5 or 6 hours. Recently I switched to Arch, and I can't trust my laptop to work half an hour anymore. It does not charge over 79% anymore on both batteries, this is after it charged all night:

~$ acpi -i
Battery 0: Unknown, 79%
Battery 0: design capacity 6426 mAh, last full capacity 5673 mAh = 88%
Battery 1: Unknown, 79%
Battery 1: design capacity 2029 mAh, last full capacity 1311 mAh = 64%

and if I unplug it, it says:

$ acpi -i
Battery 0: Discharging, 79%, 03:45:56 remaining
Battery 0: design capacity 6583 mAh, last full capacity 5811 mAh = 88%
Battery 1: Unknown, 79%
Battery 1: design capacity 2029 mAh, last full capacity 1311 mAh = 64%

ten seconds later it says only 3 hours remaining, and after maybe half an hour or 45 minutes it says the battery is empty and goes to suspend.

I have no idea what is going on. Are my batteries suddenly broken? I find the change of OS more suspicious. I have no idea where to begin debugging this though. Does anyone have an idea? Thanks a lot.

  • 2
    Just curious... How did you calculate 90% in the title? – techraf Mar 25 '16 at 8:39
  • I'd install Ubuntu alongside and verify the battery life you had earlier still exists, to start with. If that was the case, then I would compare the Ubuntu and Arch configs, with particular reference to things that controlled battery life. – Faheem Mitha Mar 25 '16 at 8:55
  • @techraf well it was a rough guess. I did not have time to clock it accurately. However, if it was 5 hours before and it is now 30 minutes, then it is 90%. – xor Mar 25 '16 at 10:20
  • @faheem-mitha I want to give that a shot, also, I have a backup of my ubuntu settings. But do you have an idea what are those famous 'things that controlled battery life'? – xor Mar 25 '16 at 10:20
  • @xxor I assume things related to ACPI. But I don't really know. – Faheem Mitha Mar 25 '16 at 10:24
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If the battery life was bad just after you made the switch then it's clearly poor power management either from the kernel or the userspace in the new distro.

If in the beginning the battery life was OK and then suddenly it messed up then it could be that one of the cells in your battery went bad. The fact that it doesn't fully charge is an indication that a cell is dead.

If you have some simple tools you could measure it. Leave the laptop off but with the power cord connected over nigh so it would charge independent of the OS. In the morning the battery should be fully charged and with a multimeter you could check if the voltage is over 11V (for your thinkpad). If the voltage is less than this then the battery is not good anymore.

If it's not the battery that went bad then you could use powertop to see what is sub-optimal from the power management point of view.

  • Thank you, @Bogdan. Is there any way to investigate if the battery cells have gone bad? It is possible, the laptop is over 2 years old. – xor Mar 29 '16 at 8:21
  • I edited the post and mentioned you could measure the battery so if this answers your quiestion I would appreciate if you could accept the answer. – Bogdan Mar 29 '16 at 8:33
  • thanks a lot. I will try doing what you said, with the multimeter. I also like the tool powertop. What I also will try to do is run a live ubuntu usb, to see if it charges better. Just didn't have time yet :) I will let you know how it turned out. – xor Mar 29 '16 at 8:37

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