Bluetooth Low Energy is designed to enable devices with low power consumption. Several chipmakers including Cambridge Silicon Radio , Dialog Semiconductor , Nordic Semiconductor , STMicroelectronics , Cypress Semiconductor , and Texas Instruments have introduced their Bluetooth Low Energy optimized chipsets over the last few years. Devices with peripheral and central roles have different power requirements. A study by beacon software company, Aislelabs , reported that peripherals, such as proximity beacons, usually function for 1–2 years with a 1,000mAh coin cell battery.  This is possible because of power efficiency of Bluetooth Low Energy protocol which only transmits small packets as compared to Bluetooth Classic which is also suitable for audio and high bandwidth data.
It used to be that when I went out late in the city, I’d play a rousing game of “How long can I keep my phone alive so I can listen to music on the way home?” I would throw my phone into airplane mode, turn the brightness down, and hope it would last until I made it back to my apartment.
Apple has since improved the way it handles battery life, though it doesn’t do everything it could to ensure your phone stays on. There are a few more tricks of the trade you can use to keep your iPhone alive as long as possible. Below, nine foolproof options: