Fuel cell power conditioners often require high step-up voltage gains to accommodate low input fuel cell voltages into high voltage busses. Traditional non-isolated DC-DC boost converters are unable to offer such as gains because of several parasitic elements and non-ideal behaviour of power semiconductors and driving circuits. Moreover, paralleled converters are also desirable to simplify power-up scaling and to reduce input/output current ripples. In this context, a very versatile non-isolated, high step-up voltage gain, interleaved boost converter is presented in this work. Steady-state analysis, simulation and evaluation of different converter structures are discussed in detail. Finally, a 500-W experimental prototype for Nexa Ballard 1.2 kW fuel cell specifications has been implemented and tested to verify the performance. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.