At this moment, ever since I installed Ubuntu on this machine, the battery status says: not present.

Looking at this answer, however, I find that /proc/acpi/battery/BAT1/info (sometimes its /proc/acpi/battery/BAT0/info, use tab complete to help) has the following info:

present: yes

design capacity: 4400 mAh

last full capacity: 4400 mAh

battery technology: rechargeable

design voltage: 11100 mV

design capacity warning: 300 mAh

design capacity low: 132 mAh

cycle count: 0

capacity granularity 1: 32 mAh

capacity granularity 2: 32 mAh

model number: BAT1      

serial number: 11        

battery type: 11        

OEM info: 11        

In accordance to this answer, I've checked the /proc/acpi/battery/BAT1/state file:

present:                 yes

capacity state:          ok

charging state:          charged

present rate:            unknown

remaining capacity:      unknown

present voltage:         10000 mV

The acpi -b command returns:

Battery 0: Unknown, 0%, rate information unavailable

Any suggestions on getting the battery info updated?