If you reduce the brightness on your screen, keeps non-use apps closed and turn off things like Bluetooth and GPS when you are not using them. You will save battery power.
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Another way to save on battery power is whenever data is not needed (e.g. at home or office using wifi or you don't have a data plan), set the prefered network to 2G instead of 3G or 4G LTE. This will not change your call quality and internet speed depends on wifi but will save battery drain.