Previoulsy I’ve just carried my digi camera gear as hand luggage and the batteries weren’t a concern. Times changes, rules change and I’d definately carry a drone as ‘hand luggage’.
So, when flying abroad with a drone, does anyone have preferred LIPO bags for batteries or advice on what the airlines look for when carry LIPO batteries.
I have zero evidence to base this on but personally I’d be buying the cheapest £1 quid bags that I could find on eBay from China.
Purely because I have a sneaking suspicion these ‘fire proof’ bags would contain a lipo battery fire no better than a plastic Tesco carrier bag would.
Again, zero evidence, so quite happy to be educated to the contrary 
I have to call shenanigans on the above tests and state they are flawed.
LiPo batteries are capable of storing large amounts of energy where as the canon cord he was using has very little energy in comparison. This means the battery can sustain a consistent burn long after the canon cord facsimile has extinguished.
When Lithium burns it can reach temperatures close to 2000 degrees C, and depending on the mass of the battery the temperature can be maintained for a significant length of time. Then there’s the specific heat capacity of the burnt material, meaning the ability to retain heat once combustion has completed.
The primary purpose of these LiPo Safe bags is to minimise the risk of puncture of the battery pack while being transported. For a smallish LiPo they can reduce some of the damage to the surrounding area, but for a high energy LiPo they are less effective than a placebo.
The batteries used in the vast majority of ‘off the shelf drones’ are already enclosed in hard plastic to protect the cells and the associated circuitry from damage, where as these bags are intended to be used with hobbyist LiPo’s that usually have a thin heat shrink envelope around them intended to keep the cells from separating.
Additionally, most airlines will have specific criteria for transporting Lithium batteries on their websites.
Heliguy also has a guide.