What does the LED light on APOLLO DUO indicate? November 23, 2021 23:59 It illuminates when charging begins, and flashes when a foreign object is detected or your phone is misaligned. Related articles What do the various colors on the LED indicator mean? What if APOLLO DUO is not charging my phone? How do I know when my CHAMP (10k) Portable Charger is fully charged? Does APOLLO DUO produce excess heat? APOLLO DUO User Manual