1. Turn off the phone, sound simple right? This is by far the simplest and most effective way of conserving your battery’s power, if your not using the phone just simply turn it off. You can do the same if you’re in an area with no reception, as your phone looks for service its draws extra power from your battery, so if you can deal without it until you get to a good area, just turn it off.
2. Use a ring tone instead of using vibrating; the vibrating option uses a lot more power than a ring tone. Although sometimes vibration is necessary for example, if you are in a meeting.
3. Turn off the backlight, if your backlight is not needed simply turn it off. If you have to use the backlight, you can shorten the length of time the light stays on. Some phones actually have an ambient light sensor and will dim when necessary.
4. Avoid unnecessary features, if you getting low on your battery indicator, don’t browse the internet or take any pictures, leave the power for the cell phone use. Using the camera will definitely decrease your cell phone batteries power, especially if you have a flash.
5. If you are not using Blue Tooth, turn the feature off. These days there are even problems with virus infected smart phones, which could in turn affect your phone.
6. Try and keep your calls short, check your guidelines from the manufacture, the talk time and battery time is totally different, the talk time is usually quite smaller.
7. The same goes for WIFI and GPS, if you are not using these features keep them off, it will drain the battery.
8. Use GSM mode on your phone vs. 3G/ Dual Mode, the dual mode will drain the battery quicker, you can get almost 50% more usage using the GSM mode.

 Basically it comes down to this, if your not using the features turn them off, all phone usage will pull the battery power down and its up to you to follow the guidelines in order to correctly charge your phone. Cell phone batteries can be quite frustrating, but with proper care you can make the life of the battery last longer.