MacBook Pro charges only until 76.35%

vlast777 · 2016-01-13 09:00:28

Hey there,

I installed Arch Linux with the latest Kernel on my MacBook Pro Mid 2009. Now what I find strange is that while using Arch the battery of my MacBook is always charged until 76.35% max.
It says it is fully charged though.

Also, the small green LED on the charging wire (which indicates wether the battery is being charged or is full) turns green and (I got a triple boot, OS X 10.11.2, Windows 10 and Arch) on the other OS' the battery is displayed as being 100% charged.

Did I forget to install any package? Or does anyone have any idea what is missing maybe?

Thanks in advance.

woodape · 2016-01-13 09:53:20

What are you using to determine if your battery is fully charged in Arch? That is, what are you using to see 76.35% and "fully charge"?

EDIT:

Also post the results of

cat /sys/class/power_supply/BAT*/charge_full
cat /sys/class/power_supply/BAT*/charge_now

Are these the same number when you supposedly have a full charge? If so, your applet is the likely culprit.

Last edited by woodape (2016-01-13 09:57:58)

vlast777 · 2016-01-13 11:31:11

$ cat /sys/class/power_supply/BAT0/charge_full
4066000
$ cat /sys/class/power_supply/BAT0/charge_now
3830000

as I read this, it seems that the applets (both, on MATE and on i3) seem to work incorrectly.
I used the MacBook for ~30 min now, so the difference might be right.

woodape · 2016-01-13 12:20:58

Do you mean that you've done some googling and found that the apps have bugs? Maybe try another app? Load up tint2 with the battery section configured or xfce4-power-manager maybe? What would be more concerning is that your power cable isn't getting it right. Does green mean fully charged or charging? Is this led displaying the correct information or not?

If you've been on the battery for a little bit that difference should be about right. Do you know what the actual capacity of your battery is or should be? Just make sure it's not about ( 4066000 / .7635 ) = 5325474.79 which would mean your apps are doing (current / design full) rather than (current / full).
try

cat /sys/class/power_supply/BAT0/charge_full_design

this shouldn't differ by too much from

cat /sys/class/power_supply/BAT0/charge_full

though batteries do deteriorate.

Allan · 2016-01-13 12:28:55

woodape wrote:

though batteries do deteriorate.

2009 mbp.... this is your answer.

woodape · 2016-01-13 12:52:27

Allan wrote:

2009 mbp.... this is your answer.

I missed that in the first post. The battery is definitely deteriorated. It would still be strange behavior for any battery app to use current charge over factory capacity to return a percent of battery charge. Within a month of using any laptop the app would never say 100% charge.

ewaller · 2016-01-13 15:32:18

woodape wrote:

2Within a month of using any laptop the app would never say 100% charge.

ewaller@turing ~ 1021 %journalctl| head -2
-- Logs begin at Fri 2015-04-10 17:35:46 PDT, end at Wed 2016-01-13 07:05:25 PST. --
Apr 10 17:35:46 turing systemd-journal[198]: Runtime journal is using 8.0M (max allowed 799.1M, trying to leave 1.1G free of 7.7G available → current limit 799.1M).
ewaller@turing ~ 1022 %cat /sys/class/power_supply/BAT0/status
Full
ewaller@turing ~ 1023 %cat /sys/class/power_supply/BAT0/charge_now
3008000
ewaller@turing ~ 1024 %cat /sys/class/power_supply/BAT0/charge_full
3008000
ewaller@turing ~ 1025 %cat /sys/class/power_supply/BAT0/charge_full_design
3008000
ewaller@turing ~ 1026 %

woodape · 2016-01-13 15:37:53

Strange, my laptops don't generally keep their full factory charge for very long, though I suppose people will have different results:

cat /sys/class/power_supply/BAT1/charge_full
5100000
cat /sys/class/power_supply/BAT1/charge_full_design
5880000

Nonetheless it seems weird that any app would use (current/full_design) instead of (current/full) for battery percentage...

ewaller · 2016-01-13 15:55:06

To be honest, I don't believe the numbers my system coughed up. After 9 months, I would expect about 10% - 20% capacity loss per year. I don;t deep cycle mine, so 10%.

In the case of this 6 year old MBP, I would have expected a loss of about 0.9^6 or about 0.53. That it is still at 0.73 is pretty good.
Of course, when my battery one day fails, I pull the little release lever and replace it with a new one. No need to even shut down

Arch Linux

#1 2016-01-13 09:00:28

MacBook Pro charges only until 76.35%

#2 2016-01-13 09:53:20

Re: MacBook Pro charges only until 76.35%

#3 2016-01-13 11:31:11

Re: MacBook Pro charges only until 76.35%

#4 2016-01-13 12:20:58

Re: MacBook Pro charges only until 76.35%

#5 2016-01-13 12:28:55

Re: MacBook Pro charges only until 76.35%

#6 2016-01-13 12:52:27

Re: MacBook Pro charges only until 76.35%

#7 2016-01-13 15:32:18

Re: MacBook Pro charges only until 76.35%

#8 2016-01-13 15:37:53

Re: MacBook Pro charges only until 76.35%

#9 2016-01-13 15:55:06

Re: MacBook Pro charges only until 76.35%

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