Abstract: A battery management unit and system for managing the state of charge of cells or batteries. Each battery management unit measures cell or battery terminal voltage and provides this information to a central controller via a communication medium. Each battery management unit monitors a plurality of batteries and can selectively charge a selected battery via a charger and switch circuit or can selectively discharge a selected battery via a load and switch circuit under the control of a controller. The controller may control charging and discharging in accordance with measurements from voltage sensors or may convey information from a voltage sensors to the central controller and receive charging and discharging commands from the central controller. Charging and discharging is controlled to maintain all batteries within a desired state of charge ranged. The central controller may selectively connect a main charger or generator to a bank of batteries associated with a battery management unit.

Abstract: A battery management unit and system for managing the state of charge of cells or batteries (B1-B10). Each battery management unit (1) measures cell or battery terminal voltage and provides this information to a central controller (3) via a communication medium (2). Each battery management unit (1) monitors a plurality of batteries (B1-B10) and can selectively charge a selected battery (B1-B10) via a charger (7) and switch circuit (8, 17) or can selectively discharge a selected battery (B1-B10) via a load (10) and switch circuit (8, 17) under the control of a controller (6). The controller (6) may control charging and discharging in accordance with measurements from voltage sensors (15a-j) or may convey information from a voltage sensors (15a-15j) to the central controller (3) and receive charging and discharging commands from the central controller (3). Charging and discharging is controlled to maintain all batteries within a desired state of charge ranged.