Abstract: A battery condition detection apparatus comprises at least the first two of a battery discharge current detector, a battery terminal voltage detector, and a battery electrolyte concentration signal detector. The battery condition detection apparatus further comprises a memory circuit for storing detection signals generated by at least the first two detectors and inputted to the battery condition detection apparatus, and a computation device for executing computation processing on output signals from the aforesaid detectors.With the foregoing structure, the battery condition detection apparatus performs computation to obtain at least one of corrected values of the battery terminal voltage and the battery electrolyte concentration in the state where the battery discharge current assumes a predetermined value, and performs the detection of the battery condition and/or the control of power generation of a battery-charging generator.