"We thought there could be a more convenient solar charger for cell phones," said one of two inventors, from Mount Ulla, N.C.

This is where a portable charger, battery pack, or power bank becomes invaluable. By connecting your phone to a portable charger, you can recharge your device without being tied to one location.

For those who are always on the go, a portable charger is a must-have. Luckily, Amazon is having an awesome sale on the ...