A low voltage LED bulb having a base that fits a standard light socket designed to receive a bulb operated at line voltage is installed in a conventional lamp, which is connected by a lamp cord to a rechargeable battery, the charge in which is maintained by a charging circuit. The rechargeable battery can be provided in a module equipped with a receptacle capable of receiving a standard plug designed for line voltage, and in this case, the lamp requires no modification other than the replacement of the standard bulb by the low voltage LED bulb. In another embodiment, the battery and charger are incorporated into the lamp.