Disclosed herein is an overcharge protection apparatus with minimized power consumption. An overcharge protection apparatus with minimized power consumption according to an embodiment includes a switching unit for controlling supply of voltage detected in a battery cell depending on an ignition-on or off state of a vehicle, and an overcharge prevention circuit for, when the battery cell is overcharged based on the voltage of the battery cell output from the switching unit, turning off a main relay, thus interrupting supply of power to a battery module, so that the voltage of the battery cell is detected only in an ignition-on state of a vehicle and power consumption is minimized, thus preventing the lifespan of a battery from being shortened by reducing a voltage difference between cells.