Battery block is battery block that includes: a plurality of battery blocks in which a plurality of battery cells is arranged by holder at fixed positions and the battery cells are connected by lead plate; and circuit board that fixes battery blocks. Battery blocks have terminal parts to be connected to circuit board at the same position. Circuit board has connection parts to be connected to terminal parts of battery blocks. By coupling terminal parts of battery blocks to connection parts of circuit board, battery blocks are connected in series or in parallel, and battery blocks are coupled via circuit board.