A voltage detection apparatus suitable for an assembled battery including a series connection of a plurality of battery cells, wherein the series connection including at least two of the battery cells configuring the assembled battery is regarded as at least one detection block of a plurality of detection blocks, the voltage detection apparatus comprising:
- a plurality of monitoring sections that each individually correspond to each detection block of the plurality of detection blocks, each monitoring section including battery input sections, a first high-potential connection section, a first low-potential connection section, a high-potential common path that is electrically connected to the first high-potential connection section, a second high-potential connection section that is electrically connected to the high-potential common path, a low-potential common path that is electrically connected to the first low-potential connection section, a second low-potential connection section that is electrically connected to the low-potential common path, and a main voltage detection section that detects a terminal voltage of a detection target battery, the detection target battery being each of the battery cells configuring the at least one detection block or the series connection of the battery cells, where the number battery cells in the series connection is smaller than the number of the battery cells configuring the at least one detection block;
- a high-potential electrical path that is provided in the monitoring section and electrically connects the first high-potential connection section and a positive electrode side of the at least one detection block via the battery input section;
- a low-potential electrical path that is provided in the monitoring section and electrically connects the first low-potential connection section and a negative electrode side of the at least one detection block via the battery input section;
- a control section that includes a high-potential input section electrically connected to the high-potential connection section, a low-potential input section electrically connected to the low-potential connection section, and a sub voltage detection section that detects a voltage difference between the high-potential input section and the low-potential input section as a terminal voltage of the at least one detection block;
- a high-potential switch that is provided in the high-potential electrical path to open and close the high-potential electrical path;
- a low-potential switch that is provided in the low-potential electrical path to open and close the low-potential electrical path;
- a high-potential external path that electrically connects the second high-potential connection section of the monitoring section corresponding to the at least one detection block at a high-potential side of the adjacent detection blocks of the plurality of detection blocks connected in series and the first high-potential connection section of the monitoring section corresponding to the at least one detection block at a low-potential side of the adjacent detection blocks of the plurality of detection blocks connected in series;
- a low-potential external path that electrically connects the second low-potential connection section of the monitoring section corresponding to the at least one detection block at the high-potential side of the adjacent detection blocks of the plurality of detection blocks connected in series and the first low-potential connection section of the monitoring section corresponding to the detection block of the plurality of detection blocks at the low-potential side of the adjacent detection blocks connected in series;
- a high-potential detection path that electrically connects at least one of the first high-potential connection section of the detection block at a highest-potential side of the plurality of detection blocks and the second high-potential connection section of the detection block at a lowest-potential side of the plurality of detection blocks, and the high-potential input section of the control section;
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- a low-potential detection path that electrically connects at least one of the first low-potential connection section of the detection block at a highest-potential side of the plurality of detection blocks and the second low-potential connection section of the detection block at a lowest-potential side of the plurality of detection blocks, and the low-potential input section of the control section.