Battery drain rate for Linpus and other distros

I would like to know battery drain rate for Ubuntu, Mandriva, Larchlinux, etc. Linpus uses between 10 and 11 watts (depending wifi and brightness).

To see how many watts your AA1 uses, do the folowing:

1. Unplug the main (so the battery drains)
2. Wait 15 seconds
3. start a terminal session and type cat /proc/acpi/battery/BAT1/state
4. multiply the 'present voltage' with 'present rate' (scale to amperes and volts first by dividing by 1000)
5. If you want to know how much battery you have left, divide remaining capacity by present rate (result in hours). Ex from below (2162 mAH / 864 mA) = 2,5 hours

For Linpus: Normal Brightness, wifi enabled, I have 12.215Volt x 0.864 Ampere =10.55 Watts (see below)
[user@localhost ~]$ cat /proc/acpi/battery/BAT1/state
present: yes
capacity state: ok
charging state: discharging
present rate: 864 mA
remaining capacity: 2162 mAh
present voltage: 12215 mV


For Linpus: Minimal Brightness, wifi disabled, I have 12.236Volt x 0.813 Ampere = 9.948Watt (see below)
[user@localhost ~]$ cat /proc/acpi/battery/BAT1/state
present: yes
capacity state: ok
charging state: discharging
present rate: 813 mA
remaining capacity: 2174 mAh
present voltage: 12236 mV

 

That's under heavy usage, right? With minimal brightness and wifi disabled my One uses ~7 Watts

 

Linpus, minimal brightness, WiFi on: 7.9W

present rate: 697 mA
remaining capacity: 1276 mAh
present voltage: 11320 mV

EDIT: Having repeated this test a few times I would question its validity as the current reported varies quite considerably for no apparently good reason.