Hi,

the following question is not Linux related in any way, but there are some pretty knowledgable people here, and I've had this question for some time so here goes...


I spend a great deal of time travelling and keep the boredom at bay watching movies and tv shows on my laptop.


My question is, how can I maximize the battery life, given than I am only watching movies?

Some options:

Play DVD from DVD player.
Play copy of DVD from Harddrive
Play copy of DVD from USB Stick

Or convert movie/Show to DivX / Xvid file and play that from DVD/HDD/USB? Has disc usage advantages but maybe decompression (processor) disadvantages?

Or will any effects be negligable and is my question moot?


For the record, the Laptop is a Dell D630, with WinXP and VLC Media player.

Changing the CPU freq down to lowest value and running it off the HDD is the best option I think. Try other power saving features here:
http://lesswatts.org/

I can play movies on my gp2x and I can set the clock freq to very low values and it will still play just fine, I'm sure this can be done with a laptop too.

Another option is to get a separate DVD player with Divx/Xvid support and put all your movies on a couple DVDs in Xvid format.

If you can bear it (I've found on my EeePC it makes very little difference in reality to watching films), turning the backlight down on the screen will save you a fair bit of power.

Things which take a lot of energy are things which move (hard drives, DVD drives etc.). If you can avoid intensively running the hard drive, and instead run if off solid state storage, that's likely to save you a bit of power. Bear in mind, your OS will be accessing the disk, and it'll still be spinning, so I'm not sure if this will actually save you any power, since the disk won't be off.

Alternatively, get yourself a live distro that'll boot off a USB stick and loads entirely into RAM, and then run the films off another USB stick (solid state). This should reduce power consumption, although you might find you don't have all the fancy ACPI stuff set up properly. You should be able to run the laptop without spinning the drives very much, and as soon as the laptop realises they're not being used, it should power them down anyway.

Best way is probably to try a few different methods, and see how you power usage varies. Then, pick the most efficient.

All of this is off the top of my head, so no guarantees what I'm saying makes any sense

- Dropping your clock speed will help.
- Turning the backlight down will also help, but could cause issues with viewing. Use at your discretion.
- Intensive use of the hard drive will run the battery down faster, whether it's "in use" by the OS or not. The OS only periodically accesses the data, while video will cause constant movement of the head.
- You could go with the solid state drive, but at this point I understand its lifespan (write cycles) is still quite a bit shorter than a normal hard drive. And they're quite expensive compared to mechanical drives.

Considered purchasing a 2nd battery?