A step-up converter is described to interface the low, poorly regulated fuel cell output voltage (70-120 V) with the higher voltage supercapacitor bank and traction drive system on a small fuel cell powered electric vehicle. The paper focuses on the design of an interleaved boost converter, in particular comparing a two inductor circuit with an alternative topology comprising a single inductor plus interphase transformer (IPT). Whilst the two circuits have identical inductive stored energies, the lower AC excitation of the inductor in the IPT topology offers performance benefits