1. Reduce display brightness
Battery is drawn mostly by the display. So turning the brightness down is the best way to minimize the battery usage. By lowering the screen timeouts (Settings -> Display), also minimize battery usage. This let your phone sleeps automatically. If we set auto brightness function is a one step solution to balancing battery life. Try to avoid animated backgrounds on your phone.
2. Kill unwanted background apps and tasks
There may be so many apps run in the background and so they need processing power. Navigate to Settings ->Applications->Running Services , you can see the background running apps. Some of these apps are need to be run all the time and some are not. If apps like gmail don't run in background, we don’t get notified of incoming mails.Apps for gaming and playing videos are not needed for background run.
Some application like ‘ Advanced Task Killer ’ can be used to kill these unwanted background running apps manually. It lists all the running apps and we can kill the apps which are not needed for background run. So we can keep our phone running smoothly and free of unwanted background processes.
3. Use Advanced services only when you need it
Services like 3G, Wifi, hotspot , bluetooth, gps also need processing power. Once GPS is activated , it constantly searches for satellites. So turn off GPS unless you need to track location or something.So turn on this features only you need it. This can improves your battery life upto a great extend. I you turn on wifi all the time, then it searches for wifi every time. If you have to transfer large files , use wifi.So you can transfer it quickly.The faster and better the connection, battery usage will be less.The same thing is applies also for hotspot and bluetooth.
4. UnInstall unwanted apps
If you no longer need an app, uninstall it. Because it will check for updates every time which is battery consuming.
5. Turn Auto Sync off
For some application we don’t need to sync all the time. For example , If we switched on auto sync for facebook contacts, it always searches for auto sync. We can sync manually it within a period of one week or more. So our contacts get updated.
6. Keep battery battery cool when charging
If your battery is become too hot , it will reduce battery life. On charging, battery may get hot.So keep it cool - charge in a cool atmosphere - otherwise battery get died.
7. Transfer data through USB
f you have to transfer files to your pc , use USB instead of bluetooth or wifi. This results faster file transfer and so less usage of battery power.
8. Use headset
Using headset while calling , listening to music and watching videos, results less usage of battery.
Some power managing apps like Deep Sleep Battery Saver can improve battery life by controlling systems which consuming power , such as screen , gps, unwanted background running apps, radio, etc.