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Their should be script which invoke when laptop runs in battery power. It change the cpu-frequency, usb_suspense etc.

Which script is done this job in Ubuntu? I need to change power saving strategy. Every time Ubuntu suspense USB device when run in battery power.

For that I have to run command manually to off the USB suspense.

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If you have an nvidia card you can install a script to manually control your video card usage to save battery power… – chrisjlee Nov 12 '12 at 20:48… – Qasim Jun 14 '13 at 14:25
up vote 2 down vote accepted

as suggested by Ubuntu and

Power Management Wiki

Measure power consumption with powertop

Before you start making any changes, it is a good idea to first get a base line for what your current power consumption is:

sudo aptitude install powertop
sudo powertop

You must be running on battery power for powertop to get the machine's current watt usage.

Using less power with pm-powersave

The pm-utils package comes with scripts for managing low-power modes.

sudo aptitude install pm-utils

In order to enter low power mode, run this:

sudo pm-powersave true

In order to leave low power mode, run this:

sudo pm-powersave false
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Thanks for quick reply. Your information is helpful. I want to know that, how ubuntu detect that laptop is now running in battery power? and what are the steps she takes to save power? – shantanu Apr 6 '12 at 17:46
1 - look at the diagram – Ringtail Apr 6 '12 at 17:49

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