System-level modeling and simulation are powerful tools to evaluate the system-level behavior of new power distribution systems. However, due to confidentiality of manufacturers, black-box behavioral models of the converters are required instead of conventional ones. This paper proposes a black-box modeling method of DC-DC converters with input current control, oriented to fuel cells power conditioning. The model is simple and the identification procedure is based on straightforward experiments. The model does not represent the internal structure of the converter, thus maintaining manufacturer's confidentiality. The method is validated using a commercial DC-DC converter for fuel-cells power conditioning.