1. Switch off the vibrate function on your phone, and use just the ringtone instead. The vibrate function uses up a lot of battery power.
2. Turn off your phone’s “back light”. The back light is what makes the phone easier to read in bright light or outside. However, the light also uses battery power. If you can get by without it, your battery will last longer. If you have to have the backlight, many phones will let you set the amount of time to leave the backlight on. Shorten that amount of time. Usually, one or two seconds will be sufficient. Many Nextel phones have an ambient light sensor, which can turn off the backlight in bright conditions and enable it in darker ones.
3. Turn the phone off. If you don’t plan on answering the phone while you’re sleeping or after business hours, just turn it off. This is probably the most effective and simplest way of extending your battery life.
4. Some phone models have a power save function which can be switched on at all times.
5. If your phone has bluetooth capability, disable it when not in use.


* If you have an old type of cell phone which does not have a Lithium Ion battery, then every once in a while, you should let your cell phone battery completely discharge and then charge it back up again. This is commonly called “conditioning”. By doing this, any memory effect should be minimized. Memory effect is the premature shortening of a battery’s life by only using it a little bit and then charging it up again. Do not do this if you have a Lithium Ion battery, as most newer phones do.


* If you have a Lithium Ion battery, do not let it discharge fully! Many newer Lithium Ion batteries have a backup reserve so this never happens, but if a Li-Ion cell is completely discharged, it will never charge fully again.
* Sometimes you have to use the phones vibrate mode. Don’t forget to switch back to a regular ring tone when you can.