Abstract: A nightlight battery charger is constructed to be normally plugged in a wall socket to function as a nightlight so that the user can easily find and locate the battery charger anytime whenever the user needs it. The nightlight battery charger includes a charger casing having a main casing and a battery cover, wherein the main casing has at least one battery compartment for at least a rechargeable battery to be disposed therein, an nightlight system which includes at least one illuminator for generating illumination, a plurality of battery terminals adapted for electrically connecting at least one rechargeable battery, a power input supplying power to light up the illumination unit, a recharging electric circuit electrically connected to the battery terminals and the power input for transmitting power to charge up the rechargeable battery t, and an exchangeable lens card for protecting the illumination unit.