I'm using both windows 7 and ubuntu-13.04 in my acer aspire 5738g notebook.

I get 3 hrs battery backup in windows 7.

But in ubuntu it shows only 1.30 hours but as it goes on to ( it shows 1.30 but within 10 min it shows 1hr ) 0.59 hours suddenly it goes off.

Even though battery is fully charged and if I unplug the chord that time, the system will also go off.

It takes hardly 1 hour to get charge (in Win7), but in ubuntu it takes around 3 hours and the level will be fluctuating.

Also,the system heats up for short time use. So please tell me how to come out from this 2 bugs.

You can email your suggestions to: raghugkatti@gmail.com


Improve Power Usage / Battery Life In Linux With TLP


Use this to improve your battery performance and to maintain temperature. So here is how to install and configure TLP:

 sudo add-apt-repository ppa:linrunner/tlp
 sudo apt-get update
 sudo apt-get install tlp tlp-rdw smartmontools ethtool


 sudo apt-get install tp-smapi-dkms acpi-call-tools tlp tlp-rdw smartmontools ethtool

tlp-rdw – Radio Device Wizard - Need to enable/disable & Power saving (Wifi / Bluetooth )

smartmontools - needed by tlp-stat to display disk drive S.M.A.R.T. data

ethtool - needed to disable wake on lan

tp-smapi-dkms ThinkPad only, tp-smapi is needed for battery charge thresholds and ThinkPad specific status output of tlp-stat

acpi-call-tools ThinkPad only, acpi-call is needed for battery charge thresholds on Sandy Bridge and newer models


Removing default Ubuntu cpu frequency config

 sudo update-rc.d -f ondemand remove 

TLP Developer

( This is not a general prerequisite for TLP but is only needed if the user decides to change the default governor. If a user issues the command without changing the TLP setting too, he ends up with "perfomance", which is quite bad for battery life.), Apply to section 3.) Processor and Frequency Scaling

The main config file of TLP is at /etc/default/tlp

  sudo gedit /etc/default/tlp


General hints:

  1. Parameters ending on _AC are effective with the power supply connected

  2. Parameters ending on _BAT are effective when running on battery

  3. Parameters containing blanks must be enclosed in double quotes like this: ""

  4. Some parameters are inactive by default; remove the leading '#' to activate

0.) General


Set to 0 to disable TLP (Reboot needed), It should be enabled so leave the default value

1.) File System


DISK_IDLE_SECS_ON_BAT=2 = You can either leave the default value (2) or you can edit it as 5, By default Ubuntu uses 5, its up to you, read the gives below help

 cat /usr/lib/pm-utils/power.d/laptop-mode

This controls how agressive the system is at trying to avoid writing to disk. The longer the disk is idle, the more power you can save.

This is only active on battery power, and it restores these values to kernel defaults when on AC power.

Defaults 5, which enables laptop mode and forces the system to wait 5 seconds whenever something asks to write to disk to flush out as much data as we can.

2.) Dirty page values


Leave the default value

Defaults 60, which means that the kernel will not start forcing process to write out file information that has been changed but not saved until 60% of usable system memory is filled with dirty information.

3.) Processor and Frequency Scaling


Remove the hash and edit it as conservative.

Its up to you what you want, you can also use ON_BAT=powersave

Select a cpu frequency scaling governor: ondemand/powersave/performance/conservative

Governor ??

The governor decides what frequency should be used.

Module Description:

ondemand        Dynamically switch between CPU(s) available if at 95% cpu load

performance     Run the cpu at max frequency

conservative    Dynamically switch between CPU(s) available if at 75% load

powersave       Run the cpu at the minimum frequency

TLP Developer

To use "conservative" over "powersave – especially on AC – should not be a general recommendation but only an option for hardware that produces excessive heat or fan noise.

4.) Min/Max frequency


Set the min/max frequency available for the scaling governor. Possible values strongly depend on your cpu. For available frequencies see tlp-stat output, Section "+++ Processor".

Hint: Parameters are disabled by default, remove the leading # to enable them, otherwise kernel default values are used.

5.) Turbo Boost


Set the cpu "turbo boost" feature: 0=disable / 1=allow ,Requires an Intel Core i processor and kernel 3.7 or later.

Important: This may conflict with your distribution's governor settings, A value of 1 does not activate boosting, it just allows it

6.) Cpu Cores/Hyper-Threads


Minimize number of used cpu cores/hyper-threads under light load conditions

7.) Kernel


Activate kernel NMI watchdog timer (0 = disabled/save power, 1=enabled). A value of 1 is relevant for kernel debugging only.

8.) Hard disk advanced power management level


Set the "Advanced Power Management Level". Possible values range between 1 and 255:

1 – max power saving / minimum performance 

Important: this setting may lead to increased disk drive wear and tear because of excessive read-write head unloading (recognizable from the clicking noises)

128 – compromise between power saving and wear (TLP standard setting on battery)

192 – prevents excessive head unloading of some HDDs

254 – minimum power saving / max performance (TLP standard setting on ac)

255 – disable APM (not supported by some disk models)

Different values for multiple disks are separated with blanks.

9.) Disk I/O Scheduler

 #DISK_IOSCHED="cfq cfq"

Select io scheduler for the disk devices: noop/deadline/cfq (Default: cfq) Separate values for multiple devices with spaces.

noop is often the best choice for memory-backed block devices (e.g. ramdisks) and other non-rotational media (flash) where trying to reschedule I/O is a waste of resources

deadline is a lightweight scheduler which tries to put a hard limit on latency

cfq tries to maintain system-wide fairness of I/O bandwidth

10.) SATA aggressive link power management (ALPM):



ALPM Aggressive Link Power Management (ALPM) is a mechanism where a SATA AHCI controller can put the SATA link that connects to the disk into a very low power mode during periods of zero I/O activity and into an active power state when work needs to be done. Tests show that this can save around 0.5-1.5 Watts of power on a typical system. ( For more check " Sources and additional help " )

11.) PCI Express Active State Power Management (PCIe ASPM):

( default/performance/powersave )

Hint: needs kernel boot option pcie_aspm=force on some machines


12.) Radeon graphics clock speed

(profile method): low/mid/high/auto/default

auto = mid on BAT, high on AC; default = use hardware defaults (Kernel >= 2.6.35 only, not with fglrx driver!)


13.) WiFi power saving mode


(Linux 2.6.32 and later, some adapters only!)


14.) Disable wake on lan

Y = Yes , N = No


15.) Audio power saving for Intel HDA

Enable audio power saving for Intel HDA, AC97 devices (timeout in secs). A value of 0 disables / >=1 enables power save.


Disable controller too (HDA only): Y/N


16.) Power off optical drive in UltraBay >> (ThinkPads only)

Set to 1 to power off optical drive in UltraBay (ThinkPads only), when running on battery. A value of 0 disables this Feature (Default). Drive can be powered on again by releasing (and reinserting) the eject lever or by pressing the disc eject button on newer models. Note: an UltraBay hard disk is never powered off.


Optical drive device to power off (default sr0)


17.) Runtime Power Management for pci(e) bus devices


Runtime PM for all pci(e) bus devices


Runtime PM for all pci(e) bus devices: 0=disable / 1=enable, Warning: experimental option, could cause system instabilities

Some times my usb mouse dongle didn't work when i plug it in usb 3 port, work fine when i plug it in usb 2 port, and all my usb 3 devices are working properly no issue.

18.) Usb autosuspend

Set to 0 to disable/1 to enable usb autosuspend feature


19.) System Start and Shutdown


Restores radio device state (builtin bluetooth, wifi, wwan) from previous shutdown on system startup:

0 – disable, 1 – enable

 DEVICES_TO_DISABLE_ON_STARTUP="bluetooth wifi wwan" 

Disables builtin radio devices upon system start:

wifi – Wireless LAN
wwan – Wireless Wide Area Network (UMTS)

Multiple devices are separated with blanks.

I have an error that my Blue tooth device is not Disabled on start up, so if you face this problem just do the following config

 sudo nano /etc/rc.local 

And add the following line before exit 0

 rfkill block bluetooth

Save & Exit & Reboot

Working with TLP

After installation TLP will be automatically activated upon system start.

To start it immediately without reboot or to apply changed settings use:

  sudo tlp start

Use the tlp-stat terminal command to check if TLP is working properly

 sudo tlp-stat

Check You system temperature

 sudo tlp-stat -t

Show battery information only:

 sudo tlp-stat -b
 sudo tlp-stat --battery 

Show configuration only:

tlp-stat -c
tlp-stat --config

Show radio devices switch state only:

tlp-stat -r
tlp-stat --rfkill

Show temperatures and fan speed only:

tlp-stat -t 

Apply Battery Settings (ignoring the actual power source):

sudo tlp bat

Apply AC Settings (ignoring the actual power source):

sudo tlp ac

You can check Which I/O you are using.

 sudo tlp-stat  # Check the section +++ Storage Devices

Trace Mode

To examine suspected problems in TLP more closely, activate trace mode in /etc/default/tlp:

 TLP_DEBUG="lock nm path pm rf run sysfs udev usb" 

Add above mentioned line in the end /etc/default/tlp , The accumulated trace data may be read at any time with

 tlp-stat -T 


 grep "tlp" /var/log/debug 

In case the trace output is missing, you have to modify your rsyslogd configuration. Create the file /etc/rsyslog.d/90-debug.conf containing

 news.none;mail.none -/var/log/debug

And restart the daemon

 sudo /etc/init.d/rsyslog restart 

Sources and additional help

There is very good support at TLP Website

Useful Config Link 1

TLP Settings


Optional tweaks

Tweak your CPU frequency with indicator-cpufreq


indicator-cpufreq will help you change your CPU frequency on the go:

 sudo apt-get install indicator-cpufreq 

Go to Dash > search for Startup > edit indicator-cpufreq add -f or copy paste the following command:

 indicator-cpufreq -f 

enter image description here


enter image description here

With the indicator you will be able to monitor your current CPU frequency & can change CPU frequency

Changing CPU frequency

Click on indicator

enter image description here

PowerSavingTweaks for Intel Graphics


 sudo nano /etc/default/grub




 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.lvds_downclock=1 drm.vblankoffdelay=1"

and run:

 sudo update-grub

Reboot to apply the changes. You do not need other tweaks as they are already added by defaults.

Additional Advice

Regularly discharging the battery

Discharge the battery atleast twice a week.

I have been using Dell utility in windows and it shows my battery health to be 94%. I had 76% before because I was not discharging it. Now that I am discharging it twice a week it's at 94% and I get almost 5 hours of battery life.


Battery discharges Read before discharging the battery


VA-API (Hardware Acceleration For Intel / AMD GPUs)


I have tested VA-API Hardware Acceleration in Ubuntu 13.04 and it save around 2 to 4 watts of battery and save cpu usage when playing movies, I would recommend it because it has no downside.

About VA-API

The main motivation for VA-API (Video Acceleration API) is to enable hardware accelerated video decode/encode at various entry-points (VLD, IDCT, Motion Compensation etc.) for the prevailing coding standards today (MPEG-2, MPEG-4 ASP/H.263, MPEG-4 AVC/H.264, and VC-1/VMW3). Extending XvMC was considered, but due to its original design for MPEG-2 MotionComp only, it made more sense to design an interface from scratch that can fully expose the video decode capabilities in today's GPUs.

Help full Links


Official Intel Drivers are using VA-API

Support video codecs

Install Intel / AMD VA-API drivers in Ubuntu

for Intel GPUs (for Intel HD Graphics as well as G45 and later):

 sudo apt-get install i965-va-driver libva-intel-vaapi-driver vainfo

for AMD Radeon GPUs (you also need the proprietary drivers!):

 sudo apt-get install xvba-va-driver vainfo

Install MPlayer with VA-API support in Ubuntu

By default, the MPlayer version available in the official Ubuntu repositories doesn't support VA-API, but you can use a PPA which provides custom MPlayer builds with VA-API support.

 sudo add-apt-repository ppa:sander-vangrieken/vaapi
 sudo apt-get update
 sudo apt-get install mplayer-vaapi

Now you need to install smplayer or vlc

 sudo add-apt-repository ppa:rvm/smplayer
 sudo apt-get update
 sudo apt-get install smplayer


 sudo apt-get install vlc vlc-plugin-pulse mozilla-plugin-vlc



Its in Option tab > Preferences, on the Video tab > General Video > Output driver set the video output driver to "vaapi":

enter image description here


Its in Tools > Preferences > Input & Codecs > Enable Use GPU Accelerated decoding

enter image description here

Helpful Links

How to correctly enable/test VA-API on Intel Sandy Bridge?

Command line flag for mplayer to use hardware acceleration?


PowerSavingTweaks for Intel Graphics

 sudo nano /etc/default/grub




 GRUB_CMDLINE_LINUX_DEFAULT=""quiet splash pcie_aspm=force i915.lvds_downclock=1 drm.vblankoffdelay=1  i915.semaphores=1"

and run:

 sudo update-grub

Added 2 new options

1 = pcie_aspm=force , 2 = i915.semaphores=1

As the test results shows it save around 0.75 to 1 watts of battery


Summary: 9.40 Watts on Average


Summary: 8.56 Watts on Average

I will try to update more test results, This update is still in beta process, i have tested only twice, please share your results also.

Helpful Links

3x+ battery life

If you google i915.semaphores=1 & i915.semaphores=1 battery save you will find very good links


An inaccurate gauge can lead to the fact that the the battery capacity values are are wrong. The battery may report that it still has 10% of capacity when in fact it has a much lower value, and this causes the computer to shutdown unexpectedly.The most adequate method to do a full discharge (100% to a minimum of 3%) consists of the following procedure:

Fully charge the battery to its maximum capacity (100%); Let the battery "rest" fully charged for 2 hours or more in order to cool down from the charging process. You may use the computer normally within this period; Unplug the power cord and set the computer to hibernate automatically at 5% . If you cannot select 5%, then you should use the minimum value allowed, but never below 5%;

Leave the computer discharging, non-stop, until it hibernates itself. You may use the computer normally within this period; When the computer shuts down completely, let it stay in the hibernation state for 5 hours or even more; Then plug the computer to the A/C power to perform a full charge non-stop until its maximum capacity (100%). You may use the computer normally within this period.

After the calibration process, the reported wear level is usually higher than before. This is natural, since it now reports the true current capacity that the battery has to hold charge. Lithium Ion batteries have a limit amount of discharge cycles (generally 200 to 300 cycles) and they will retain less capacity over time.

Many people tend to think "If calibrating gives higher wear level, then it's a bad thing". This is wrong, because like said, the calibration is meant to have your battery report the true capacity it can hold, and it's meant to avoid surprises like, for example, being in the middle of a presentation and suddenly the computer shuts down at 30% of charge.

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