Woops... I'll file that away with the "don't bring your key knife in your hand luggage" rule I forget about every time, it's been with me on a plane to US 4 times now, big enough it shouldn't be there. I put Li batteries from my camera, GoPro, Phone, all sorts in my case, no one has ever cared.
EDIT: I'm not saying it's ok to do here, just that i'm retarded enough to do it.
they also state that they should be wrapped in such a way that the electrical contacts can not come in to contact with anything metal. They are getting picky about batteries since peoples hover board things keep blowing up, and MH370 was carrying a shed load of batteries in the hold . .