Contactless cell apparatus

A cell apparatus that emits and receives AC power via magnetic field resonance includes a cell interface and a circuit to generate a magnetic field when emitting the AC power and to generate an AC current when exposed to a magnetic field from an external device. The cell apparatus also includes a switch or sensor to determine whether a charging mode or a discharging mode is active. Because the cell apparatus emits and receives AC power via magnetic field resonance, it can be charged and discharge without electrical contact with another device.