I am a Ubuntu user since years and I have not come across this problem till date.
My battery drains off immediately after I unplug my AC power.
The options I tried:
1) I checked the battery state with : cat /proc/acpi/battery/BAT0/state
present: yes capacity state: ok charging state: charged present rate: 0 mA remaining capacity: 392 mAh present voltage: 12476 mV
Initially it was showing charging state: charging after 5 minutes it started displaying as charged! Based on that, if i remove my AC Power it shows low battery notification.
2) When I run acpi : acpi -b
Battery 0: Unknown, 9%
The battery state shows as unknown. But initially when we plug-in to AC adapter
acpi -b Battery 0: Charging, 9%, 13:04:00 until charged
3) When I check the same with : upower -i /org/freedesktop/UPower/devices/battery_BAT0
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C09:00/PNP0C0A:00/power_supply/BAT0 vendor: HP power supply: yes updated: Thu Nov 1 16:06:40 2012 (20 seconds ago) has history: yes has statistics: yes battery present: yes rechargeable: yes state: charging energy: 4.2336 Wh energy-empty: 0 Wh energy-full: 33.1128 Wh energy-full-design: 33.1128 Wh energy-rate: 5.6052 W voltage: 12.474 V time to full: 5.2 hours percentage: 12.7854% capacity: 100% technology: lithium-ion
In the power stats output, It says 5 hours to charge completely, yet if I charge it even more than 5 hours and unplug the AC power, it cribs again stating LOW BATTERY !!
The same thing does not happen with Windows 7.
Any suggestions/help will be greatly appreciated.