Battery does not work more than 4hrs even i do not use multimedia files too.....

I dont know what kind of phone you have but sounds like you need a new battery. If you still dont want to buy a new one try some of these: 1. reduce screen brightness 2. turn off unnecessary utilities like bluetooth, WIFI, 3G, etc 3. Use a dark wallpaper 4. Vibration takes up more battery 5. use a simple theme rather than a heavy complicated one 6. dont charge your phone for looong periods (overnight)
If you buy a new one make sure its authentic/branded or else you may end up with the same problem again. good luck

If a recharable battery is more than 3 - 4 years old then the battery could be wornout. Rechargeable batteries have a finite number of charge and discharge cyclesand will lose their charge capacity over time, i.e. won't charge to 100% andgradually the charge reduces until the battery won't charge up atall. ORThe battery shows a 100% charge but when the adapter is disconnected thebattery drops off to zero capacity in a very short time. Ifthe battery drops to an unacceptable charge level then the battery needs to bereplaced.