Abstract: A rechargeable battery assembly includes a battery array and a battery controller. The battery array includes a number of batteries, and each battery includes a battery module and an integral module controller. The batteries may be connected in various configurations to form a battery array that is able to provide a power supply of almost any desired voltage. The module controller regulates charging of the battery module and is able to disconnect defective battery modules from the circuit. During a charging cycle, the module controller disconnects fully-charged modules from the charging circuit. During a discharging cycle, if a battery module becomes inoperative, the module controller disconnects the inoperative module, so that the battery array does not become inoperative because of one or more inoperative battery modules.