Originally Posted by
Flubber2012
Is the concern loose/spare lithium batteries contacting something that conducts elecricity and short circuiting?
That's why it's OK to have lithium batteries powering all kinds of devices but not OK to transport spare batteries?
That is correct.
Also, you want the spare batteries in the cabin (carry-on) so that they are accessible if a fire does start and the crew can fight the fire.