I now have quite the collection of USB power banks from the small to large capacity and am having an issue using them to power a cheap Ikea single LED light. The lower capacity power banks happily power the light for many hours i.e. until they're clearly out of charge. My problem is the bigger ones refuse to power the same light for more than a minute. I've tested these and they are capable of delivering close to their rated capacity to other loads. My question is what's different about the Ikea light that causes the bigger power banks to turn off the power after around 1 minute. According to my USB power meter the Ikea light draws less than 10mA. My research suggested I may need to connect pins 2 and 3 of their USB outputs to convince them to play along but that hasn't worked. It seems these power banks don't like very light loads which may make some sense if their only function is to charge other devices.