system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does battery powered electronics (such as a remote or an electrical toothbrush) lose power as the battery is weakened and not work at full power till the battery is dead?
gpt
A battery's voltage decreases as it is drained of energy.

Think of voltage (electrical potential) as water pressure. You hang up a bucket of water and open a hole on the bottom to shower. The water pressure at the start is strong from the weight of water pressing down. However, as the water drains, the pressure weakens and it gets more difficult to wash yourself.

This is the same thing that happens with the motors and lights powered by batteries. As the battery drains, these parts lose power gradually until they stop working.

One way to prevent this is to put in regulators that fix the pressure/voltage at some level rather than have it decrease over time. Newer electric toothbrushes have this. They will run at full power and only start weakening when they are low on battery.