Battery system with practical voltage detection

A battery system comprising:

• a battery having a plurality of series-connected battery cells that can be recharged;
• a voltage detection circuit that detects the voltage of each battery cell;
• a discharge circuit connected to each battery cell to discharge each battery cell;
• and
• a decision circuit that judges the condition of the connection between a battery cell and the voltage detection circuit from the detected battery cell voltage measured by the voltage detection circuit;
• wherein the voltage detection circuit measures discharge voltage of a battery cell with the discharge circuit in the discharging state, and the decision circuit compares the detected battery cell discharge voltage with the normal voltage to judge abnormal connection between the battery cell and the voltage detection circuit.

A battery system comprising:

• a battery having a plurality of series-connected battery cells that can be recharged;
• a voltage detection circuit that detects the voltage of each battery cell;
• a discharge circuit made up of a series-connected discharge resistor and discharge switch connected to each battery cell to discharge each battery cell;
• a constant voltage circuit connected in parallel with the discharge resistor of each discharge circuit;
• and
• a decision circuit that detects the condition of the connection between a battery cell and the voltage detection circuit and the leakage current of the input-side of the voltage detection circuit from the detected battery cell voltage measured by the voltage detection circuit;
• wherein the discharge voltage of a battery cell is measured with the discharge switch in the ON state, and the decision circuit determines abnormal detection by the voltage detection circuit from the measured discharge voltage.