intermittent sound form usb speakers when powered by usb battery bank

HI i am trying to power a pair of logitech usb speakers via a usb battery bank for my comicon outfit there is a problem though when powered by a usb wall charger it works flawlessly although when the leds blink on my xaiomi battery bank on either of the two usb ports the speakers go *pup* and turn off (although i am playing a song) dose anyone know of how i could fix this issue or not if so ill deal with it turning off