The main goal of the research presented in this paper is to find an analytical solution for an electromagnetic energy harvester with double magnet. A double magnet configuration is defined as a structure in which two magnets, either attracting or repelling, are positioned at a constant distance from each other. Analytical dependencies that govern the shape of electromechanical coupling coefficient curves for various double magnet configurations are provided. In the subsequent step of the analysis, resonance curves for its vibrations and the corresponding recovered energy were determined for the selected dual magnet settings using the harmonic balance method. These characteristics enabled us to ascertain the optimal resistance and estimate the maximum electrical power that can be harvested from the vibrations of the double magnets.