A battery charger with a fixed frequency charging signal at or near the resonant frequency of the battery to be charged is presented. The present invention utilizes a microprocessor to modulate a current source at or near the resonant frequency of the battery to be charged without the use of a PLL. To simplify conventional modulated battery chargers, the PLL or other methods of phase correction are removed, reducing most of the calculation requirements for adjusting the phase angle, thereby reducing the piece count and ultimately cost and complexity. The result is a solution wherein charging occurs at or near the resonant frequency of the battery, and although suboptimal, the results are superior to traditional charging methods.