Never having to run out of power is definitely absurd
Adding water should provide electrolyte, which forms a primary battery with the positive and negative plates placed in the alarm clock, and is powered by the primary battery principle
< p>(Someone also bought one and discovered that it also had a button cell inside, I don't know if it is true or not)The energy consumption of LCD is very low, so the energy of this reaction should be enough
You can also refer to the principle of piles of fruit.