There is provided herein a portable automatic external defibrillator having a controller a charging circuit controlled by the controller to charge at least one capacitor using a battery, and a discharge circuit controlled by the controller to discharge the capacitors using a pair of electrode pads. The defibrillator also has a board separable into two portions at a bisection, each portion having a respective electrode pad on an upper surface thereof. Each of the controller, the charging circuit, the discharging circuit, and the battery are located with one or the other of the two portions.