Tips on how to extend battery life

[infernosoft]

I'm travelling oversees (economy class, so no electric plugs to use) and was wanting to know how I can get the most out of my battery (use my laptop as long as possible).

I think the following would help (plz let me know if i'm wrong).

1. Turn wireless off
2. Turn one CPU Off (since I have dual core duo)
3. Reduce brightness (which btw, can I reduce any lower than the brightness applet on the panel will let me??)

Thanks

[Simian Man]

What do you want to use the laptop for? If you can, booting to init 3 does wonders for battery life .

[stefan1975]

turn off bluetooth
beforehand install and run (as root) 'powertop' (yum install powertop) and follow all advices
user hibernate and set your laptop to sleep when not in use
set powersafe settings (powerdevil in kde) to aggresive so it will make the laptop to use as less power as possible
if possible replace cd-drive with extra battery pack
upgrade battery to a more powerful one

[Firewing1]

Turning wireless off & reducing brightness will help, and disabling bluetooth will give you a large boost as well. I don't think turning off one CPU will help that much, but you should consider enabling throttling (cpuspeed) to reduce your CPUs core speed when they aren't in full use.

There's also a few other tricks you can do like disabling HAL polling and increasing the writeback time - install "powertop" and run it as root for more information on how to do this. Another thing that may be interesting is if you don't need to access the disk very often, load what you need into RAM using ramfs and then park the hard disk.

[infernosoft]

Basically, almost all I want to do is watch a movie or two on my way to Europe.

Originally Posted by Simian Man

What do you want to use the laptop for? If you can, booting to init 3 does wonders for battery life .

What's init3? It sounds like a just text based system lol...am i right?

Originally Posted by stefan1975

turn off bluetooth
beforehand install and run (as root) 'powertop' (yum install powertop) and follow all advices
user hibernate and set your laptop to sleep when not in use
set powersafe settings (powerdevil in kde) to aggresive so it will make the laptop to use as less power as possible
if possible replace cd-drive with extra battery pack
upgrade battery to a more powerful one

What's powersafe? And how can I access it in GNOME?

Originally Posted by Firewing1

Turning wireless off & reducing brightness will help, and disabling bluetooth will give you a large boost as well. I don't think turning off one CPU will help that much, but you should consider enabling throttling (cpuspeed) to reduce your CPUs core speed when they aren't in full use.

There's also a few other tricks you can do like disabling HAL polling and increasing the writeback time - install "powertop" and run it as root for more information on how to do this. Another thing that may be interesting is if you don't need to access the disk very often, load what you need into RAM using ramfs and then park the hard disk.

I ran powertop and it suggested that i disable HAL, but first I'd like to know exactly what it is that I'm disabling. So, basically, what will I lose once i disable HAL?

And, also since I'm primarily wanting to watch movies, I think that the idea of just loading it to the RAM and watching it is very appealing. Is there a tutorial for that?

Thanks everyone.

[zackf]

If you're going to be watching movies or doing something HDD intensive, putting them on a Flash drive instead of running them off the HDD might save you some battery. DVD Drive is a killer.

[infernosoft]

Originally Posted by zackf

If you're going to be watching movies or doing something HDD intensive, putting them on a Flash drive instead of running them off the HDD might save you some battery. DVD Drive is a killer.

O, so copy the movie from my internal HD onto my external USB drive, and play it from there?

[zackf]

depends on what kind of drive it is, but if it's just a USB flash drive (not an external Hard Drive) then yes I would recommend that. The flash drive will eek out a little power from the USB port, but you'll save battery life in not having to spin the internal drive for two straight hours.

[infernosoft]

well, could I just load the movie into the RAM (I have 2Gig RAM, and the movie is 700mb)?

is that even possible?

and then, maybe 'suspend' the HD somehow? or is this all just wishful thinking...?

[infernosoft]

BUMP. please, i'm leaving in a couple days and need to figure this out

[Firewing1]

I would follow zackf's suggestion of a USB key since it barely takes any power and will save you the RAM space, but if you'd like to use the RAM approach then you'll need to create a tmpfs mountpoint and copy the movie file to it like this:

su -
mkdir /ramstorage
mount mount -t tmpfs -o size=1G,mode=0777 tmpfs /ramstorage

This will create a 1GB RAM volume in /ramstorage that will only consume as much RAM as required, to a maximum of 1GB. It will be accessible to everyone (0777 permissions) until it is unmounted (the contents will be cleared) or you reboot, so if you copy the movie file there and play it you should not be using your hard disk. You can suspend HDD manually using the "hdparm" utility on the command line, but Fedora should do this for you automatically after a few minutes of inactivity.

Regarding HAL, you're not completely disabling it but simply disabling the optical disk polling, meaning instead of having the computer "realize" when you've inserted a disk, you'll have to double-click the CD/DVD drive volume before it loads the disc contents... Not a big deal since you're not going to be using the DVD drive on the plane anyways

[infernosoft]

stupid mistake....nvm sorry

[stevea]

You're getting some great advice here IMO.

The only thing I can add is perhaps relevant to your next trip. LiIon batteries have a load of issues. The best way to keep your battery is to discharge it to ~30% of total change and put it in a ziplock in your fridge. The worst-case storage condition for a LiIon battery is fully charged and warm, which is approximately what happens when you work with a fully charged battery in a busy laptop. I really wish laptops had the ability to tell the batter to hold at ~30% charge or else to fully charge in preparation for an untethered experience.

[awaisclub]

What if the OS itself is on the usb. Would it be helpful?
Don't know that the whole OS is always on RAM or can be on harddisk too.
Just wana ask for general knowledge

[stefan1975]

disabling as many services as you can (stuff that you do not need anyway) will help some as well (system-config-services), so you just have those things running and eating away cpu cycles that you absolutely have to.

stefan

PS! bumping your thread after a mere 16 minutes is so lame.