Originally Posted by
dtremit
They are, in fact, imposing a stricter rule than required by governments and IATA in order to simplify things. Technically, it is legal to check any device < 5kg with a battery < 100Wh capacity, but they don't want agents to have to ask people what the storage capacity of their laptop battery is.
Practically speaking, the only device most travelers will ever carry that's available with a battery > 100Wh is a laptop (or a dedicated power bank, which is covered separately); hence, that's what they restrict.
Actually the vast majority of people don't know (or really care) about the tech they use. As long as it powers on and does what they want, that's all they care about. Except for some workstation class laptops, most laptop manufacturers are keeping their battery capacity below 100Wh. It's easier to tell people laptops should not go into checked luggage, but the battery is also a secondary reason. The primary reason is value. When they tell travelers not to put anything expensive in luggage, there's a reason. Theft and liability. You (the traveler) have been advised not to put stuff like that or jewellery or anything else of significant value into checked luggage...