This is going to be a two-part post, since it became a bit lengthy during the writing :-)
There are a few simple and obvious things to take into consideration, when you want to prolong your off-the-electric-grid time:
- Minimize the amount of components with movable parts
- Turn down the screen brightness
- Disable wireless transmissions
Then there is at least one not-so-obvious thing that you can do:
- Shut down unneeded applications.
- Choose the graphics card appropriate for your type of work
- Make your CPU run more slowly
Movable componentsComponents with movable parts will use more energy than a lot of other things in your laptop. There are two main such components in your laptops: optical drive and hard drive.
Ask yourself how often have you used your optical drive in the last year.Chances are, you haven't. In general we don't burn CDs anymore as we used to. We use USB drives (flash or otherwise) when we need to physically transfer data to someone else. We install software from either online sources or the same USB drives can be used for that purpose as well. And even if you've installed something from a CD or a DVD during the initial setup of your laptop, how often do you need to do it now?
The thing is, that optical drive, even if you don't use it, will still be an active part of your system. It will be checked during the boot of your laptop, to see if there's a bootable media in it. This will also add a few annoying seconds to your boot time. During operation of your system, it will be checked for contents whenever you open your file management application, such as Windows Explorer, or even when you have an "Open" or a "Save" dialogue window open in your Word, Excel or any other application. Every time you do this, a considerable amount of electrical power is spent.
So, if you still have an optical drive in your laptop, consider removing it.
Chances are, you will want to fill up the hole in the side of your laptop with something. There are plastic kits that fit into your optical bay, that are made for just such a purpose. It's possible your laptop actually came with such a thingy. If not it's easy to order one from the Internet and they shouldn't cost more than a few bucks or euro. They usually look like this:
Apart from saving you some electricity it will also make your laptop a bit lighter, as well.
Regarding the standard hard drive, there's not too much to say. If you can afford it, replace it with a Solid State Disk (SSD). For one thing it's going to spend less electricity, because there are no movable read/write heads and no rotating magnetic platters. Another thing is that it will make your laptop feel run much faster than before.
Another, and probably more significant consumer of power in your system is the component that you cannot be without. Your display. The larger it is and the higher resolution it has, the more power it needs. Brightness is also a very important factor. With the screen at full brightness versus minimum one, you can get an additional half an hour out of your battery. That is, of course, an estimate, but not too inaccurate one.
If you're working on battery power, chances are you're either on the move or you're somewhere where infrastructure is less-than-perfect. In either case it's probably also likely that the work that you have in mind is not of an online sort. If that is the case, then turn off your wireless radios.
You have at least wireless radio in your laptop, most likely a Bluetooth one as well and maybe even a 3G/4G also. All of these devices are constantly looking for connections. And often, if there are no connections, that makes them look even harder, which takes even more power.
Good solution is to turn them off.
If you are running Windows 8, there is a "Flight Mode" option, that you can enable, by clicking on the network icon in your taskbar and then selecting Flight Mode from the top of the menu. If you don't need wireless but still require Bluetooth, then select the second option from above instead.
That's it for part one. Part two will talk about some less obvious approaches, that may also prove useful.