A tattoo machine and wireless battery power supply comprising: a tattoo machine that comprises a body, a motor, and a power supply connection end, and a wireless battery power supply that comprises a battery and a tattoo machine connection end. The tattoo machine connection end comprises a depressed cavity at the bottom of which are power supply surface connectors and a magnetic material portion. The power supply connection end comprises a backplate protrusion, which may comprise one or more O-ring grooves, one or more O-rings, power supply pin connectors, and a magnet. The tattoo machine connection end and the power supply connection end are configured to matingly and electronically engage one another, such that the backplate protrusion is substantially within said depressed cavity, the O-rings frictionally contact an interior surface of the depressed cavity, the magnet and magnetic material portion are magnetically coupled.