Most smartphones have large displays and touchscreens, reducing battery-life. Here is how you can get the most out your smartphones battery: 1-keep the display brightness at around 50 per cent, as it drains the most power; 2- turn off 3G, Wi-Fi, Bluetooth when not in use. Most phones have a dual-mode option which lets you switch between 3G and 2G networks automatically. For best performance, set this as GSM only; 3- avoid using the speakerphone: use the earpiece or earphones. You can also carry a spare battery in case you are travelling and cant charge your phone regularly.