Abstract: A battery charger is disclosed which is adapted to receive batteries of different sizes for charging. The charger comprises a separate support for each of the batteries, and different sizes of batteries are supported at different levels in the charger. A charge current is supplied to the batteries by a circuit which includes a timer for regulating the charge time. In order to insure that only batteries having known electrical characteristics are mounted in the charger, means are provided to lock out batteries not having a predetermined feature, for example, a positive terminal of a particular size. The charging time is regulated in accordance with the size of the battery, and a detector is provided to sense the size of batteries in the charger.