A reconfigurable battery has at least one bank of statically joined series connected battery cells, each cell including a positive and a negative pole. The poles connect through switches to respective output connections. Activating a set of processor controlled switches reconfigures at least some of the battery cells into a configuration to provide a voltage across the output connections. The output battery voltage may vary intermediately between zero volts and the maximum voltage produced by the series connected battery cells.An alternative configuration of switches divides groups of series connected battery cells into separate battery banks that permit other battery cell configurations. Duty cycle modulation of the switches allows intermediate control of output voltage with reduced switching transients. Reconfigurable battery cells used in combination with an electric motor permit selectable speed control and battery regeneration schemes matched to motor output.