This paper deals with the analysis of boost interleaved DC-DC converter with a coupled inductor on the same magnetic core. The advantage of the coupled inductor over the non-coupled case is investigated. The ripple current equations as an input current for the boost operation mode and the ripple current in individual phase of the interleaved converter using coupled inductor are explained analytically, supported by simulation and experimental results. The novelty of the paper is an investigation of current ripples of interleaved boost converter operated over 50% of duty ratio and utilization of the converter in the application of electrically driven vehicle.