I bring you a prototype of a small homemade hydrogen fuel cell genset, which I have designed to power small devices such as charging cell phones, up to powering a small radio controlled truck using the same components as a full size fuel genset or powerpack, being quite versatile, emitting only water vapor and heat.
Figure 1 Hydrogen PEM fuel cell rc truck
To carry out this prototype, a 12W commercial fuel cell has been used, which transforms hydrogen, combined with oxygen in the air, into water vapor, electricity and heat.
Figure 2 Diagram of a (Proton Exchange Membrane) PEM fuel cell
The required hydrogen is stored in a small cartridge in the form of metal hydride, which means that it is chemically exchanged with a metal (M) in the following way, as compared to doing it by pressure like commercial gas cylinders.
The only drawback of this system is the low energy density in terms of mass, storing up to 7.6% w/w in hydrogen.
The control of the fuel cell is done by an Arduino Nano, whose task is simply to measure operating voltage and purge the excess water that forms on the anode to prevent the fuel cell from flooding, which would damage the cells during operation. Also, it protects it when it operates for long periods of time in open circuit or with low load, avoiding its early degradation.
Figure 3 Simplified wiring diagram of the genset (left) and integration with the radio-controlled truck
Fuel cells operate on current demand, varying their total voltage. Therefore, I use a typical boost-buck converter, such as the one used to power basic circuits, at the output of this one, stabilizing the voltage. In parallel, a Li-Ion 2S, 14500, 680 mAh battery is connected, so that it can absorb the power peaks demanded, with an estimated peak power (1C) of up to 17W, in combination fuel cell and batteries.
Here I share the links of the videos I published, explaining better this concept and its manufacture. During the tests you will see that the autonomy is somewhat limited, although I store up to 1g of hydrogen, about 1850 mAh usable in the fuel cell (considering its performance), only 0.2g is used due to the cooling of the hydrides and the numerous purges I did to clean the stack during startup. Nowadays, I am working to improve it and part of it, you can see in the second part which is more practical and fun where my radicontrol truck works completely with hydrogen.
Genset Video, Part 1
Hydrogen Radio Controlled Truck Video, Part 2