A year ago, I bought a dell e1505 notebook cheaply.but I have replaced almost all of the laptops accessories besides battery during the year.whether your laptop runs five or six hours on a full charge with no extra messing around, or whether it dies in less than an hour, there are ways to extend the battery life through software settings.

The dell e1505 notebook came equipped with a number of profiles optimized for different tasks. These are shown above, and for the main part, they are designed for the computing task, rather than for the extending the battery life to the maximum. In other words, they assume that you want DVD playback to proceed without any stumbles, and that you’d never want your hard drive to spin down or video output to wink off during a presentation.

In none of the profiles to they drop the CPU processing speed (see graphic to the left) below the halfway point, 3 on a scale of 1 to 5. The settings they are most willing to sacrifice are the LCD brightness and the cooling method. Lower LCD brightness certainly extends battery life a little but it’s so easy to manually adjust the LCD brightness from the laptop keyboard that I don’t worry about getting it right in the profiles. In fact, when I use my notebook outside during the day, I usually find I have to run the LCD brightness up to the maximum (tapping Fn-F7 a few times) just to see.

The real value, or nuisance value, of the factory set battery life profiles are the automatic shutdowns, In the aggressive battery saver modes, the hard drive spins down every time it’s not accessed for a minute or two, and the LCD winks out if you don’t hit a key or move the mouse every minute. While the LCD coming on and off can be annoying, it probably doesn’t waste extra power, but I believe that frequently spinning the hard drive up and down rather than just keeping it going can waste more power than it saves. Likewise, hibernate and standby can help conserve e1505 battery life if you’re going to remain in that mode for a while, but going into hibernation every five minutes and having to wake up again is probably a wash, because hibernate is actually doing work saving an image of your desktop and then shutting down the power.

When you power up again, the system is doing a lot of work to restore your desktop, as opposed to preserving it in a low power state. Standby does just that, extending laptop battery life by preserving everything in memory but shutting down all of the user interfaces. A laptop might be able to preserve it’s current state on standby for a day or two on a full charge, but it’s really for moving from the cafe back home, or between your office and a meeting.