The only thing I can find online that is useful, which is similar to what @
Loren Pechtel wrote above is following, clearly stated on Cathay Pacific.
cathaypacific.com/cx/en_US/travel-information/baggage/controlled-and-banned-items/lithium-batteries.html
Which clearly states that Audio/Visual Batteries, Lithium or not can be stored in your Checked In, if they are inside the device in which they are used. Which is how I transport them.
You can not find this info on most airline websites, cough (Air Asia).. If any can find it, please post the relevant link.