[svlug] question - my laptop won't charge to 100% even though plugged in and using AC power

Deyan Bektchiev svlug at bektchiev.net
Sun May 3 13:47:59 PDT 2009

On Sun, May 3, 2009 at 1:01 PM, Darlene Wallach
<freepalestin at dslextreme.com> wrote:
> On Sun, May 3, 2009 at 1:52 AM, Deyan Bektchiev <dejanb at gmail.com> wrote:
>> On Sat, May 2, 2009 at 1:05 AM, Darlene Wallach
>> <freepalestin at dslextreme.com> wrote:
>>> Chris,
>>> On Sat, May 2, 2009 at 12:55 AM, Chris Miller
>>> <lordsauronthegreat at gmail.com> wrote:
>>>> On Sat, May 2, 2009 at 12:42 AM, Darlene Wallach
>>>> <freepalestin at dslextreme.com> wrote:
>>>>> I always use my laptop plugged into AC power. The last few days I've noticed
>>>>> the yellow light is blinking and will not turn green. When I hover the mouse
>>>>> over the plug it shows the computer is charging. Does this indicate I need a
>>>>> new power supply? The power supply gets warm - it used to get hot. I just
>>>>> bought one last summer, July 2008, just before I left for Gaza. Or does this
>>>>> indicate another problem?
>>>>> Thank you for any insight. Thank you for your attention.
>>>> Lithium Ion batteries do loose their ability to hold a charge as time goes by.
>>>> I have noticed that sometimes the battery's internal meter becomes
>>>> "confused" and fails to recognize that it's holding as much as it will
>>>> be able to hold in its degraded state.
>> I had a ThinkPad battery that simply "died" and would not recharge at
>> all and was showing the exact same symptoms. The ThinkPad power
>> manager (unfortunately only available in Windows) showed that the
>> battery was bad and I called Lenovo to have it replaced under
>> warranty.
>> Run "cat /proc/acpi/battery/BAT*/*" and look at the output to see if
>> the battery is really holding charge.
> $ cat /proc/acpi/battery/BAT*/*
> alarm:                   365 mWh
> present:                 yes
> design capacity:         4400 mWh
> last full capacity:      3656 mWh
> battery technology:      non-rechargeable
> design voltage:          11100 mV
> design capacity warning: 365 mWh
> design capacity low:     182 mWh
> capacity granularity 1:  644 mWh
> capacity granularity 2:  8 mWh
> model number:            245XIX
> serial number:           0001
> battery type:            LiOn
> OEM info:                OEM
> present:                 yes
> capacity state:          ok
> charging state:          charging
> present rate:            unknown
> remaining capacity:      3605 mWh
> present voltage:         12516 mV
It looks like your battery capacity is degraded by 15-20% but is
should still be OK - I wouldn't worry much about the blinking light.

If you want to try and restore some of the capacity, completely
discharge and charge the battery a couple of times. Discharge it until
the laptop would shut down or go to sleep and then charge to 100% (or
as much as it charges - you can use the ACPI information to monitor
the charging).


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