A storage battery device (13; 14) comprising: a battery group that includes a plurality of battery cells connected in series; a charge-and-discharge control FET unit (34, 37) that is connected to a low potential side of the battery group and includes at least a pair of N-channel MOSFETs (34-1, 37-1) source terminals of which are back-to-back connected; and a drive controller configured to generate a drive control signal according to a potential level of the source terminals and configured to output the drive control signal to gate terminals of the respective N-channel MOSFETs (34-1, 37-1) of the charge-and-discharge control FET unit (34, 37) characterised in that the drive controller comprises: a constant voltage circuit configured to generate a certain constant voltage based on the potential level of the source terminals with the battery group as a power supply to supply a constant voltage power supply; and a level shifter (52, 54) configured to operate with the constant voltage power supply as a power supply, configured to perform level shift on a discharge control signal or a charge control signal having a signal level based on a power supply potential level with the battery group as a power supply, and configured to output the discharge control signal or the charge control signal having a signal level based on the potential level of the source terminals, wherein the discharge control signal and the charge control signal are configured to operate as the drive control signal. a battery group that includes a plurality of battery cells connected in series; a charge-and-discharge control FET unit (34, 37) that is connected to a low potential side of the battery group and includes at least a pair of N-channel MOSFETs (34-1, 37-1) source terminals of which are back-to-back connected; and a drive controller configured to generate a drive control signal according to a potential level of the source terminals and configured to output the drive control signal to gate terminals of the respective N-channel MOSFETs (34-1, 37-1) of the charge-and-discharge control FET unit (34, 37) characterised in that the drive controller comprises: a constant voltage circuit configured to generate a certain constant voltage based on the potential level of the source terminals with the battery group as a power supply to supply a constant voltage power supply; and a level shifter (52, 54) configured to operate with the constant voltage power supply as a power supply, configured to perform level shift on a discharge control signal or a charge control signal having a signal level based on a power supply potential level with the battery group as a power supply, and configured to output the discharge control signal or the charge control signal having a signal level based on the potential level of the source terminals, wherein the discharge control signal and the charge control signal are configured to operate as the drive control signal. a constant voltage circuit configured to generate a certain constant voltage based on the potential level of the source terminals with the battery group as a power supply to supply a constant voltage power supply; and a level shifter (52, 54) configured to operate with the constant voltage power supply as a power supply, configured to perform level shift on a discharge control signal or a charge control signal having a signal level based on a power supply potential level with the battery group as a power supply, and configured to output the discharge control signal or the charge control signal having a signal level based on the potential level of the source terminals, wherein the discharge control signal and the charge control signal are configured to operate as the drive control signal.