Off the top of my head, both lithium polymer/lithium ion cells are much more temperature sensitive when compared to most liquid fuels. When flying fpv quadcopte

Off the top of my head, both lithium polymer/lithium ion cells are much more temperature sensitive when compared to most liquid fuels. When flying fpv quadcopters in cold weather, (speaking from a anecdotal hobbyist experience here), I get a much lower maximum current for the first minute or so until the individual cells warm up due to the internal resistances. This translates to less total raw wattage. Total battery capacity is reduced as well. I imagine a big challenge would be keeping the batteries at a happy temperature. A quick google search shows the Solar Impulse team ran into this problem: (https://www.theverge.com/2015/7/11/8933295/solar-impulse-sustains-battery-damage-after-record-flight https://www.theverge.com/2015/7/11/8933295/solar-impulse-sus...) Edit: The above in regards to providing reliable electric power. Disregarding this, the main downside by far is energy density of currently available batteries. From https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density, a kilogram of gasoline has about 53x as much energy as a comparable 1 kilogram lithium ion battery. Gasoline 46.4 Lithium-ion battery 0.36–0.875 (MJ/Kg)