External lithium batter chargers

[crewmeal]

What's the latest ruling on taking these external usb power banks as hand luggage so I can charge my iPad inflight? Googling doesn't give you a definite answer one way or the other. Most say don't pack them in hold luggage which I wouldn't otherwise it defeats the object. I also have a free single charge one given by EE, however after reading a horrendous story about it heating up I don't really want to take it.

[highflyer40]

Don't almost all aircraft have USB/power points in the seats nowadays? Unless LCC obviously.

[crewmeal]

Not Egyptair 738's