Earlier quoted context omitted.
Current drone batteries are a much higher fire risk than a hydrogen blimp.
It's worth noting that hydrogen is orders of magnitude more energy-dense, by mass, than lithium-ion batteries. As a benchmark: the DJI Phantom weighs roughly 1kg, and its battery can store about 80kJ of electrical energy. I found a NASA study [1] which estimated that the energy released when a li-ion battery combusts is roughly 2x the usable energy capacity. So let's say that a battery fire would release 160kJ of ene…
I'm not so sure that kind of energy release would be entirely harmless.