system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why I can't recharge normal household batteries? When they build them they charge them, so why can't I?
gpt
They don't charge them when they build them. The current is generated by a chemical reaction, and the batteries are built with the required ingredients for the chemical reaction. They don't build an empty battery and then charge it up. When you make a "battery" by sticking nails in a lemon, you don't have to charge up the lemon first.