The open fuel cell is perfect to show the working principle of a fuel cell. It is possible to record current-voltage diagrams and to calculate the power output of the cell with it.We used the OFC to demonstrate normal operation principles of PEMFCs during our visit at the Luisenschule in Muelheim and at the Sommer Uni of the University Duisburg-Essen. At the Sommer Uni we were recorded technical parameters which we documented here. Unfortunately it is not possible to generate enough power with just one open fuel cell for a normal power consumer as e.g. LED lights, fans etc. The voltage of a single fuel cell is just not high enough.
That changes when you connect multiple open fuel cells in series. In this case the voltages of the single cells will add up. In addition to that, we achieved a further boost of the output voltage by using a cheap DC/DC boost converter. Referring to the according data sheet, this converter is mentioned to produce an output voltage of 5V with a varying input voltage ranging between 0,9 V and 5 V.
With our 2-cell stack we tried to power a small light chain. That worked, but the power output was rather small, so the lights were shining a bit dimmed. It turned out that the output voltage of the DC/DC converter was quite low while operated under load of the LED lights.
In order to boost the performance of the LED lights, we decided to combine two of our 2-fuel-cell stacks resulting in an quite improvised stack consisting of 4 cells altogether. With this setup we were able to generate enough power for a small light chain to shine bright and also to make the shown fan to spin fast enough to generate a refreshing breeze. However, under the load of the LED lights or the fan, the output voltage of the DC/DC converter dropped to roughly 3,5 V, while the voltage of the improvised stack was something around 2,4 V. Sadly, with this performance of the improvised fuel cell system it is not possible to charge a smartphone. However we were able to use the offspring of the original open fuel cell for some practical applications. Still – some improvements have to be done to the DC/DC converter. Maybe this is the chance for your “open converter project”.
