BATTERY PACK, BATTERY SYSTEM, AND DISCHARGE METHOD

摘要

PROBLEM TO BE SOLVED: To appropriately discharge internal current of a battery pack and improve maintainability.SOLUTION: A battery system comprises: a plurality of battery packs 200 each including a lithium ion battery 16, a main circuit that is connected in series to the lithium ion battery 16 and is to be a power supply path, a second protective circuit 62 that is connected in parallel to the lithium ion battery 16 and consumes internal power under a predetermined condition, and switching means for connecting the lithium ion battery 16 to the second protective circuit 62 while disconnecting the lithium ion battery 16 from the main circuit; and a second IC 18 that is connected to the main circuit and the second protective circuit of each battery pack 200 and controls input/output to/from each battery pack 200. The second IC 18 reports abnormality of the battery pack 200 when having detected output current or voltage from the protective circuit in the battery pack 200.