Power bank
Alternatively called a battery pack, portable battery, or portable charger, a power bank is an external battery used as a backup accessory for your portable electronic device. It lets you charge your device after the included battery dies. They are commonly used to supplement smartphone and tablet batteries for extended use away from a power source. Traditionally, power banks are third-party components that are not included with the purchase of the device.
Common features of power banks include LED (light-emitting diode) battery status indicators, Micro-USB (universal serial bus) or USB-C power connector, and standard USB power output. To find the percentage of your device's battery a power bank can charge, check how many milliampere hours (mAH) it can store and compare that number to your device's battery.
Backup, Battery, Battery terms, Hardware terms, LED, Phone terms, USB