Yalcinsonat1/Getty Images If you own a smartphone, be it an Apple iPhone or a Samsung Galaxy, you’ve likely heard of the “20-80 charging rule,” which maintains that keeping your phone charged between 20% and 80% is the best way to keep your phone’s battery healthy and extend the life of your phone. In today’s world of information overload, it can be hard to separate fact from fiction, and there are plenty of myths about smartphones floating around out there (no, you...