This paper develops the design of a batteries charger. This charger works as power factor correction and delivers a DC voltage to the battery. To this, a bridgeless boost topology is used, this and the battery are modeled and then, an adaptive control strategy is developed. This have into account the battery changes to tune the controller and keep sinusoidal the input current and keep it in phase with the main. Furthermore, the output voltage is controlled to a constant value with a suitable ripple to charge the battery. The outcomes of the simulation of this development are presented, where the average total harmonic distortion and power factor were 4.78 % and 0.9877 respectively. Finally, the conclusions are presented.