How to Choose a Power Bank for Your Phone. Portable Charger Comparisons, fast charge, USB ports, battery life, iPhone, android, iPad, capacity. Anker, Samsung, Lumsing. Knowing how to choose a power bank for your phone is an important step when just leaving the house for a day, much less planning a long or overseas journey. As overseas travelers are focused on connectivity more than ever before, a reliable, affordable power bank is a must-have for anyone setting out to explore faraway lands.