Adopt reversible charging technology.
Currently, some smartphones come with a reverse charging feature that allows the phone to transfer power to another device via cable or wireless charging technology. With this option, the user can power up their phone to let others know they are okay or to make an emergency call.
Using an external battery
An external battery or “power bank” is a very useful resource for recharging several phones when power is not available. Today there are different types of batteries, depending on the amount of energy they can store, which can also be used to charge the battery of a laptop or tablet.
Charge your phone with your car
During a power outage at home, users can use the car battery to power their smartphone by connecting the cell phone to the vehicle port with a USB cable.
Although it may take several hours for your device to charge depending on the battery capacity of your device, this is the most efficient way to ensure that your phone is 100% charged.