Abstract: A battery charger is disclosed including a main housing which receives an adapter therein. The adapter receives batteries or other devices to be charged therein. The adapter has alignment projections and multiple levels therein for accommodating many different sizes of devices or batteries to be charged. In addition, the adapter is modular in that it can be modified yet still be received by the main housing for receiving additional devices of different sizes. The adapter seats with the main housing, and has integral attachment members for engaging a base plate thereto. Ventilation apertures are also provided within the main housing, the adapter, and the base plate for allowing sufficient heat dissipation during the charging process.