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Comment by lupusreal | Hacker News Reader

> Ukraine uses about 4000 drones per day

Use, or expend?

Mainly expend. Most of them, after release lives for minutes up to half an hour or so. Often they aren't even charged to full capacity.

I think most electric drones can't stay in the air for half an hour. Why not charged to full capacity?

Also... if it is true that drones live for less than 2 sorties on average, that makes their returnable use pointless because launching them one-off doubles the range as they don't need to store charge for return trip, don't you think? Also i assume, primary cells that are not rechargeable, can have higher capacity than rechargeable batteries.

> Also i assume, primary cells that are not rechargeable, can have higher capacity than rechargeable batteries.

Interesting, do you have more information on state of the art non-rechargeable batteries? I would assume they just use normal LiPo cells anyway and just charge them once, ideally at the factory. Cheap, light (compared to the warhead at least), can deliver enough current.

Zinc-Air primary cells have about twice the energy density of Li-ion cells. https://en.wikipedia.org/wiki/Comparison_of_commercial_batte...

I expect them to have hundreds if not thousands of drones in surveillance/recon roles, in which they'd mostly be reusable. If that "4k used per day" figure actually means the ones expended per day I'd be pretty surprised.

Even the recon drones have a fairly short lifespan due to EW.

I find that extremely hard to believe, unless you're exclusively talking about sending drones to attack a specific location with a time crunch, I don't see any reason why a drone wouldn't be charged to full. Especially since that figure probably includes unarmed drones used for ISR

The documentaries I have seen on YT suggest Ukraine is building >1M drones annually, which would be enough to cover going through 4K daily, ballpark. Lots of those FPV videos do show various "low charge" warnings, maybe it just doesn't make sense to fully charge something that's basically a guided bullet on a one-way trip?

FPVs fly a few KM before getting to a target, so the battery will be low by the time they get to the part worth recording. There's no need for a return trip since it either finds a target or is intentionally ditched.

Also they use li-ion cells which can be run to a lower voltage than a lipo, which is normally what the flight controllers are configured for out of the box.

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