Actually, this said external battery, not power bank, but maybe that's what they meant. I looked all over just to find that. I would be wary of buying these things online except maybe if it's Amazon, and even then...I wonder if they sell phones. I would almost like to get another Samsung Galaxy S5, despite the problems I've had with it. Should I wait a while longer just in case the new battery magically starts working, or should I take it back now? I still have the old one. Is there any way I can test it myself and not have to rely on what someone else says? By the way, if anybody on here has a (presumably) used S5 for sale, please let me know. I can pay by money order or maybe card, possibly even cash.