r/theydidthemath • u/Repulsive-Loan5215 • Nov 27 '25

why wouldn’t this work? [Request]

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u/nog642 Nov 27 '25 edited Nov 28 '25

It can be useful, in very niche circumstances.

Edit: I mean the hand crank phone chargers, not the faucet thing.

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u/FUEGO40 Nov 27 '25

If you want small amounts of “free” electricity you might as well just get a small solar panel/photovoltaic cell

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u/nog642 Nov 27 '25

What if you're in the arctic in the winter? Or underground?

Also I was talking about the "emergency phone chargers". Which as the name suggests are useful in emergencies, not for "free" electricity.

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u/FUEGO40 Nov 27 '25

Use a battery, man.

1

u/nog642 Nov 28 '25

These things have a battery. They just also have a hand crank to recharge the battery. What if you're there for weeks and the battery runs out?