The EH-7P is a charging AC adapter that is used to charge the EN-EL15c an EN-EL15b rechargeable Lithium-ion battery while it is in the camera’s battery compartment and the camera is connected to the charger.
EH-7P charging AC adapter is also used with the MH-33 charger, compatible with EN-EL18d, EN-EL18c and EN-EL18b batteries.