This simple application can help you increase the standby time of your device: Automatic WiFi automatically disable your WiFi radio when you do not need and reduces the battery consumption .
You can also specify to automatically turn off WiFi again , if you turn on the device or when you enter a specific location ( requires a radio cell and therefore does not work on the WiFi- only tablets !). In addition , the application can regularly search for available networks to connect and re- disable WiFi if no suitable network is found.
Wi -Fi generally uses less energy than a mobile data connection , so your phone, it makes sense to keep the WiFi radio on, whenever a Wi-Fi network is in range
For More Info Google Play