[tristanj]

These items are dangerous. The FAA limit for power bank capacity is 100Wh (~27000mAh), which is 360kJ of energy. A hand grenade has approximately 700-800 kJ of energy.

Two powerbanks contain the same amount of energy as a hand grenade.

[drum55]

That's a kind of meaningless comparison. Peanuts are about 8kJ per gram supposedly, by your measure we should ban even small amounts of peanuts on planes because 100 grams of them contain more energy than a hand grenade. Without talking about the time frame over which the energy can be released you'd have to make sure that everybody went onto the plane completely naked lest their clothes ignited.

[SoftTalker]

Not good enough, body fat contains about 35kJ per gram. So nobody with over 1lb of excess body should be allowed on board. People are known to occasionally spontaneously combust.

[fragmede]

I thought that was proven to be people falling asleep with a cigarette in their hands and lighting a blanket on fire.