Battery system

A battery system that is compact and lightweight and capable of reducing the effects of induction components even when the wiring length connecting between plural battery elements has become long. A battery module (213) contains multiple battery cells (217-11 through 16) formed into cuboid shapes and connected each of the battery cells. The bus bars (W11, W12) (first current flow path) that electrically connect the battery cells (217-11 through 13) in series, and the bus bars (W14, W15) (second current flow path) that electrically connect the battery cells (217-14 through 16) in series are respectively installed so as to maintain a mutual specified gap. The electrical current flow directions in the bus bars (W11, W12) and the bus bars (W14, W15) are set in mutually different directions at an inverter unit (R1) configured from a positive terminal (Tp14), a negative terminal (Tn13), and a bus bar (W13).