Originally Posted by PedroDaGr8

Many people carry very high capacity Li-ion batteries now too, especially on longer flights. Some of the largest ones are equivalent to 10-20x larger than a phone battery. Though laptops still tend to have the largest batteries (though not always true), an off-brand powerbank is much more likely to fail catastrophically. I also read somewhere that there is oxygen lines, or something like that, that run near the lavoratory. If you have ever messed with pure oxygen, it can make things that are rather docile turn into raging infernos FAST! You can melt through a 0.5cm 1/4" thick piece of steel using a cigarette dipped in liquid oxygen. Liquid oxygen is a very dangerous side hazard of my job and not one you take lightly.

Having lost a cousin due to an onboard fire in a small airplane (he was the pilot, his last radio transmission was smoke in the cockpit before it crashed), the idea is quite scary.