Originally Posted by StuckInYYZ

That said, there is one catch about the power banks (at least coming out of China). They have to be legit (including serial numbers being visible). I had two power banks where the serial numbers were rubbed off and the airport security team (once in PEK, once in PVG) would not allow them through. (thought they were knock-offs) For me it wasn't a biggie as both were the oldest power banks in my collection and this was on the way home (hence, I just plugged into the power socket). Great way to dispose of them, but it's definitely a warning for everyone.