Currently, there are a lot of renewable energy potential research focusing on the potential of photovoltaic and fuel cell. However, the main problem in photovoltaic and fuel cell application is only able to generate low output voltage. In order to increase the voltage, converter device is required before applied to the load. The dc-dc boost converter is one kind of converter which used for increasing output voltage. However, a conventional boost converter is only optimally worked in 2-3 times conversion rate of the input voltage, so this converter can not supply the load with high voltage rate. This research implements high voltage gain converter based on B×B topology for fuel cell application. The advantages of high voltage gain dc-dc boost converter is having conversion rate and high efficiency also has a simple implementation and it will be compatible to be applied in renewable energy sources with dc low voltage, such as photovoltaic and fuel cell. From the implementation results, the high gain dc-dc converter can improve the voltage gain about 4.5 times and able to be implemented with fuel cell application.