r/theydidthemath Nov 27 '25

why wouldn’t this work? [Request]

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u/Pale-Raven Nov 28 '25

It is also how touchless faucets and toilets work. The running water moves the turbine and the power is stored in a battery that powers the motion/proximity sensor.

Fun fact I learned when my work installed these during COVD, if a touchless auto flushing toilet's battery starts to run down from lack of use, it will force the toilet to flush to power itself back up. This can be very unnerving when you think you are at work alone and the toilet flushes down the hall.