# [SOLVED] Battery not charging past 90% with kernel 3.16.

## Jhedron

I've been seeing some odd behavior with my ThinkPad T510 battery since about the time I upgraded the kernel to 3.16. When I plug in my laptop to charge the battery, it charges fine up until it reaches 90%. After that point, the battery will not charge and the estimated time-to-full continues to increase. This happens with my old battery and the new battery which I just installed this morning. There's nothing in the log to indicate any problems. The timing seems to indicate something in the kernel, but I won't be able to test with < 3.16 until next week. Is there some configuration setting somewhere I'm missing?

Relevant information:

Machine is a Lenovo ThinkPad T510

sys-kernel/gentoo-sources-3.16.3 (happened w/ 3.16.2 and 3.16.1 as well)

sys-power/upower-0.99.1

```
$ upower --dump

Device: /org/freedesktop/UPower/devices/line_power_AC

  native-path:          AC

  power supply:         yes

  updated:              Fri 19 Sep 2014 11:29:57 AM EDT (2109 seconds ago)

  has history:          no

  has statistics:       no

  line-power

    warning-level:       none

    online:              yes

    icon-name:          'ac-adapter-symbolic'

Device: /org/freedesktop/UPower/devices/battery_BAT0

  native-path:          BAT0

  vendor:               LGC

  model:                45N1011

  serial:               52614

  power supply:         yes

  updated:              Fri 19 Sep 2014 12:04:40 PM EDT (26 seconds ago)

  has history:          yes

  has statistics:       yes

  battery

    present:             yes

    rechargeable:        yes

    state:               charging

    warning-level:       none

    energy:              84.3156 Wh

    energy-empty:        0 Wh

    energy-full:         93.5952 Wh

    energy-full-design:  93.5952 Wh

    energy-rate:         4.3734 W

    voltage:             12.882 V

    time to full:        2.1 hours

    percentage:          90%

    capacity:            100%

    technology:          lithium-ion

    icon-name:          'battery-full-charging-symbolic'

  History (rate):

    1411142680   4.373   charging

Device: /org/freedesktop/UPower/devices/DisplayDevice

  power supply:         yes

  updated:              Wed 31 Dec 1969 07:00:00 PM EST (1411142706 seconds ago)

  has history:          no

  has statistics:       no

  battery

    present:             yes

    state:               charging

    warning-level:       none

    energy:              84.3156 Wh

    energy-full:         93.5952 Wh

    energy-rate:         4.3734 W

    time to full:        2.1 hours

    percentage:          90%

    icon-name:          'battery-full-charging-symbolic'

Daemon:

  daemon-version:  0.99.1

  on-battery:      no

  lid-is-closed:   no

  lid-is-present:  yes

  critical-action: HybridSleep
```

Last edited by Jhedron on Thu Oct 09, 2014 9:12 pm; edited 1 time in total

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## Roman_Gruber

well.

A new battery needs some cycles to reach full capacity.

Full capacity refers to a certain value from 80-100 percent of nominal capacity. Over time and over some charging cycle the full capacity degrades down to something around 75-80 percent, which is still okay for a battery.

Batteries have their own protection and charging logic on them. The reference values change from cycle to cycle.

If you get 90 percent it is just a displaying bug, as the 90 percent could be your current 100 percent of your battery. I would not worry about it.

I would personally suggest you forget about the idea that a battery is defect or the charging circuit is defect when it stops at 90 percent. It could be the charging circuit in the battery which prevents it or adapts it. It could be wrong calculated full capacity. These values are derived from the logic in the battery.

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## kernelOfTruth

related ?

http://marc.info/?l=linux-kernel&m=141061280127213 [linux-3.16.y: acpi-battery fixes]

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## cwr

I've sometimes had to remove and replace the battery to persuade the charging circuit (in fact, on an old Thinkpad) that the full battery capacity on an ageing battery has changed.

Will

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## Jhedron

 *kernelOfTruth wrote:*   

> related ?
> 
> http://marc.info/?l=linux-kernel&m=141061280127213 [linux-3.16.y: acpi-battery fixes]

 

It seems it may have been. I upgraded to 3.17.0 today and the problem went away.

Thanks everyone for your responses.

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## Ant P.

ThinkPads have a special BIOS feature to limit the maximum battery charge to prolong its life. There's a kernel driver to adjust it; it should show up as a configurable knob in /sys/devices somewhere if your model's supported.

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