To avoid to use functions unnecessary: If you know that you will not be able conectarte by a long period or you have left little battery, avoids the use of the camera (particularly of the flash), of the connection to Internet, bluetooth, GPS, etc. Only uses the functions that in truth you need. A very common example of this is the referring one to bluetooth, to much brings it people caught all the day without using it. The USA a device free hands with cable: The Bluetooth devices put an extra load to the use of the battery, if you use free hands with cable, not only you will save load in your reserve, but you will have a better sound, which they have verified personally with all the Bluetooth earpieces that I have tried, mainly when have left half of load, do not have the same fidelity, you perhaps do not go away so sophisticated, but you will be able to continue speaking when others are looking for a public telephone. To administer the Duration of the Calls: This can seem something obvious, but in whichever occasions no perhaps I have listened somebody to say has left little battery, cuts to the call soon to continue speaking by 20 minutes until the telephone dies, if we mainly rationed the amount of minutes that we spoke, with little load, it is possible to arrive at the end of the day with a pair of barritas of reserve. To speak instead of to send e-mails: In the case of having a telephone with capacity of shipment of post office, if you have something fast that to say, he is better to make a call and to leave a message in the voice mail, that to send a mail, the connection of data spends of 3 to 4 times more energy than a voice connection. In conclusion, there are many forms to save battery load and to use it efficiently, the important thing is to know our true needs and the characteristics our equipment. I hope that these advice are you useful and you put who them in practice so that you can mantenerte connected to your friendly instead of a wall connection.