[Samsung Galaxy Mini] im abcd:
With great features comes short battery life but there are various ways in which you can extend the battery life uptill a certain extent .

Try these methods :

Use Android’s Built-in Battery Usage Screen

There’s a screen built into Android that most casual users probably don’t even know about, and it can tell you exactly what is killing your battery. Head into Settings –> About Phone –> Battery use to see what has been killing your battery life.

From this screen, you can usually see what apps are the worst offenders, and you will probably notice that the biggest problem—at least, the biggest one that we can fix—is actually the backlight on the phone. Personally I’d prefer to talk less to other humans, but that isn’t always an option!

Note: on my phone, I’ve already configured the backlight to not be very bright—normally that number would be a lot higher.

Adjust the Backlight to be Less Bright

Since we’ve already determined that the backlight is usually the biggest problem, you should probably adjust the settings. Head into Settings –> Display –> Brightness, where you can choose to automatically adjust, which usually works fairly well, or you can just turn the brightness down to the lowest acceptable level.

You should make sure that the screen timeout value is set to turn off quickly as well.

Disable Your Wi-Fi When You Don’t Need It

Wi-Fi can really speed up accessing data on your phone, but it can also be a big drain on the battery if you don’t need it enabled, especially when you are out and about… The phone will try and scan for a wireless network even though you may not want it to.

To enable Airplane mode, you can head into Settings –> Wireless & networks–> Airplane mode.

You can easily toggle the Wi-Fi on or off with a widget or shortcut—there’s a built-in widget included in Android phones, or you can use the AnyCut or BetterCut utilities to create your own shortcuts to directly turn them on or off without requiring a widget.

Disable Bluetooth if You Don’t Use It

If you aren’t using a wireless headset, there’s no reason to have Bluetooth running all the time, and you should probably cut it off to save the battery life. If you never use it at all, head into Settings –> Wireless & networks–> Bluetooth

You can also enable or disable the Bluetooth when you do need it, using the power widget.

Use the Power Widget to Easily Toggle GPS, Bluetooth, Wireless, and Screen Brightness

Android includes a built-in Power Widget that can easily toggle these settings on or off—just long press on the background of one of your screens, choose Widget –> Power Control to add it to the screen. You’ll notice in this example screenshot that I’ve got my GPS enabled but I’m not using Wi-Fi or Bluetooth at the moment—the icon all the way on the right lets you easily toggle the screen brightness settings.

This is probably the simplest and easiest thing that you can do to save your battery without having to dig into the settings all the time.

Disable Apps that Sync Constantly

The built-in Email application (not the Gmail one, which uses Push technology) can suck the battery badly, because it syncs on a too-regular basis, especially when you have lots of accounts—each one of them is set to sync every 15 minutes. You’d be better off setting it up to sync manually, but if you want it to sync automatically, you should set it to sync less frequently.

Open up the Email application, head to your account, and choose Account settings –> Email check frequency from the menu. Change this to something more like an hour… or never. You can always hit refresh manually when you want to read your email.

The same thing holds true for other accounts, like Twitter clients, which are even less important to update all the time. For Seesmic, you can head into Settings –> Background Updates from the main screen. For the official Twitter app, the settings are similar.

The Facebook application polls automatically in the background, and you can customize the refresh interval for that as well—if you don’t need Facebook updating all the time, you should set this value as high as possible.

From the main Facebook screen—the one with the icons—head into Settings –> Refresh interval from the menu.

Disable the GPS Location Features

One of the biggest battery sucking features on my droid is the GPS… When I have navigation going, the battery dies far too fast, so I end up having to keep it plugged in the whole time I am driving. This makes sense… but what you might not know is that a lot of other applications use the GPS as well.

You can also change the GPS to use wireless networks, and uncheck the option for Use GPS satellites—this will make the GPS a little less accurate, but it will save your battery. Note that you probably want the real GPS enabled if you’re using Google Maps Navigation.

Additionally, you should turn off the geolocation features in your Twitter client, weather application, or whatever other apps that you really don’t need them in. If you want to keep it enabled, that’s great, just realize that it does drain the battery, so uncheck this option to help.

Use a Task Manager to See What is Always Running

It is a wise decision to have a copy of Advanced Task Cleaner or a similar application installed on your phone to help you kill applications that don’t need to be running, but more so that you can see what exactly is launching itself repeatedly in the background. You can setup an auto-kill list for applications you don’t use that often—make them cut off when you shut off the screen, or after an interval.

Note: If you’ve configured your application settings to not pull down lots of data or do checking in the background, it’s not quite as important to keep tasks killed all the time—that’s really what kills your battery, not having them sitting idle.

You can also configure advanced task manager to show you CPU usage for each app, which is a more useful meter than memory usage when it comes to battery life.

Disable or Remove Applications That You Aren’t Using

Once you have identified the application that you don’t want running all the time, check in the settings to see if it can be removed from running in the background. Some applications will give you an option for notifications that can be turned off if you don’t need them, making the application not check in the background so often.

It should go without saying, but we’ll say it anyway—you should remove the apps that you don’t need anymore, especially the ones that are draining your battery as determined from the android battery panel or task manager. Head into Settings –> Applications –> Manage Applications and then you can click the Uninstall button for an app.

Disable Home Screen Widgets You Don’t Need

If you’ve got loads of widgets that are pulling data from the web, that means they are likely pulling down data in the background all the time. You should try not to go overboard with these, or remove the ones you don’t actually need.

Disable Animated Wallpaper

Yeah, that sweet animated wallpaper doesn’t help your battery any. Get rid of it for a small extra battery savings.

Keep the Battery from Getting Too Hot

One of the quickest ways to kill a battery is to leave it out in the sun—try and keep your phone somewhere that isn’t too hot whenever possible. You’ll end up needing to replace the battery a lot quicker if you don’t.

And my personal recommendation is to close your phone in the night which will save your battery . You can also use call forwarding if you get important calls in the night .

Hope this helps :)

All the credits of these tips goes to http://www.howtogeek.com