Fuel cell auxiliary power unit

A fuel cell auxiliary power unit is like a little machine that uses a special kind of energy to make other things work. You know how when you use a battery, you need to replace it with a new one when it runs out of energy? Well, a fuel cell auxiliary power unit is different because it can create its own energy to power things without needing to change batteries.

It works like this: inside the machine, there are special little things called fuel cells that take in two different things – hydrogen and oxygen. When these two things mix together inside the fuel cell, they create electricity, which is like magic energy that powers all sorts of things. The electricity can be used to power lights, phones, or even big machines like airplanes or cars.

The cool thing is that when the fuel cells inside the auxiliary power unit make electricity, they also make something else – heat and water. This is like a little bonus because the heat can keep things warm and the water can be used for other things too.

So, in short, a fuel cell auxiliary power unit makes its own energy by mixing hydrogen and oxygen together inside little fuel cells, which then creates electricity, heat, and water. It's a cool and efficient way to power things without needing to rely on batteries all of the time.