Jackery has announced its Apple MFi certified product that combines a compact, built-in external portable charger and battery in a single Lightning power cable. It’s designed to extend iPhones' and iPads' battery power, allow charging from any USB power outlet, and be used to transfer files to computers or other devices.

The $19.99 Jackery Jewel (http://www.jackery.com/jackery-jewel) can be plugged into a mobile device for up to 20% extra battery power while on the go and can also be used as the primary power and charging cord, says Julie Wang of Jackery. The 39.4 in lightweight cable features a polymer lithium ion battery and a high-efficiency circuit board embedded in a nine-layer protective shell.

The battery can purportedly keep an iPhone 6S charged for up to three extra hours of standby time. The battery and circuit board are encased in a rugged plastic shell.

A built-in LED on the battery and charger case gives users information on battery levels. In charging mode, an LED flashes and illuminates in red, green or blue to indicate levels, and users can also push the cable's power button to check battery levels. The LED also indicates levels in recharging mode and will continue flashing until the battery is fully charged.