I have been using Ubuntu 11.04 on DELL Inspiron 14R (N5010) laptop for last three months. Before I switch to ubuntu my laptop battery used to give 2.5 hrs to 3 hrs back-up. But since I have been using ubuntu, it has been reduced to 1hr to 1.5 hrs at max. I tried following commands:

$ cat /proc/acpi/battery/BAT0/state

which gave result as

present: yes

capacity state: ok

charging state: charged

present rate: 1 mA

remaining capacity: 4400 mAh

present voltage: 12407 mV

then I tried $ acpi -b

the result was..
Battery 0: Unknown, 100%

when I gave command as $ upower -i /org/freedesktop/UPower/devices/battery_BAT0

the result was..

native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0

model: DELL W7H3N08

serial: 7114

power supply: yes

updated: Sat Nov 24 11:25:34 2012 (21 seconds ago)

has history: yes

has statistics: yes

battery

present:             yes

rechargeable:        yes

state:               fully-charged

energy:              48.4748 Wh

energy-empty:        0 Wh

energy-full:         48.4748 Wh

energy-full-design:  48.9595 Wh

energy-rate:         0.011017 W

voltage:             12.408 V

percentage:          100%

**capacity:            52.9253%**

technology:          lithium-ion

Someone please let me know, what is going wrong with my laptop? How can I get charging with full capacity?