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Comment by spookthesunset | Hacker News Reader

It’s remarkable what energy dense batteries have enabled. Drones and the entire quadcopter scene wouldn’t be possible without them.

Some maneuvers made on a 5” quad can pull more than 100 amps on a 6S, 22V battery. That is around 2,200 watts—more than most consumer microwave ovens! The fact that a battery weighing no more than half a kilogram can supply this much power almost instantly is truly remarkable.

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To be fair, people were doing a LOT with model airplanes ~60 years ago with kerosene engines.

I don’t think modern quads would be possible with combustion engines. They aren’t precise and responsive enough. Modern brushless motors paired with some pretty kickass electronic speed controllers and flight controllers create a pretty amazing thing.

I mean modern quads can fly in “3D” mode and almost instantly reverse the direction of all the motors so the quad can fly in all orientations, right side up and upside down.

Have the combustion engine drive a generator not the props, it's still more energy dense (but only scales so small).

Keep in mind that there are exactly a grand total of 4 moving parts in a quadrotor drone. This is the core reason for their success, robustness, ease of use and all.

If all quadrotors needed oil, gas, vibrated like crazy (bad for IMUs), had 100+ moving parts (engine, servo gears, etc...), weighted at least 1-2kg, ran super hot and noisy... we would not have had the "drone revolution".

I guess it's not just about the energy density, but also about how quickly you can convert the stored energy to kinetic energy. Maybe this is something where the modern batteries are much better and combustion engine/generator combo. Parent comment mentions being able to get 2000W out of those small batteries.

Combustion engines have much higher power densities than batteries

Those batteries still cost ~$40 USD each from a high end brand. Hoping those can fall in price a bit too.

Some goggle DVR, can check out the current amp draw on bottom left. https://www.youtube.com/watch?v=b4V9DMUtTPY

Neither would my 300 gram plane that can fly for an hour and 60 kilometers. Technology is great.

Do you get live video over cellphone networks at that weight?

No, it has an analog transmitter on it that has a range of roughly 5 km. Video over cell isn't very widespread, though it should be.

you're extolling energy density (energy per unit volume) but your example is about power delivery (energy per unit time). the former is the real progress. the latter just needs low internal resistance, which is a thing we've had.

Zero-Point Energy Modules when?

When we find atlantis

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