Batteries are more dangerous than I realised. I work in a Post Office and last year new regulations regarding dangerous goods were brought in. We have to ask everyone what is in the parcels they are sending and can refuse to accept them if they contain certain items, including batteries not in their original packaging. Lithium batteries are apparently even more dangerous and we can only accept them with the item they are meant for. Apparently if crushed they can set on fire. As a lot of mail (even in this country) goes by air this could have serious implications if something caught fire whilst a plane was in the air, for those onboard and also for anyone on the ground. Royal Mail are so serious about this that they scan all parcels and if thought to include something dangerous they will destroy the package, only letting the sender know if they put their return address on it.