Abstract: A method and apparatus are disclosed for charging series connected batteries, particularly nickel cadmium. The means and method described are used for charging single or multiple batteries. In the form of multiple batteries the batteries are charged sequentially in time. A programmed microprocessor controls the constant current source which provides a mean constant charging current to the battery under charge. By monitoring battery voltage during charging the processor will terminate charging when certain conditions occur. In addition, provision is made for termination of battery charging upon occurrence of certain abnormal conditions.