Battery system with battery cells held in a stack by metal bands

A battery system comprising:

• a battery block having a plurality of stacked battery cells that are rectangular batteries;
• insulating separators made of plastic and sandwiched between the battery cells that make up the battery block to insulate the series-connected battery cells;
• and
• fastening components that hold the battery cells of the battery block;
• wherein the fastening components comprise:
• a pair of endplates disposed at the ends of the stacked battery cells;
• and
• metal bands disposed at battery block side-walls extending in the stacking direction of the battery cells and connected at both ends to the endplates to hold the battery cells in a stack;
• wherein an insulating separator comprises:
• an insulating plate section that intervenes between adjacent battery cells;
• and
• insulating walls connected to the insulating plate section that cover both battery cell side-walls and are disposed between the battery cell outer side-walls and the metal bands;
• wherein the insulating walls and the insulating plate section are formed from insulating plastic as a single-piece;
• and
• wherein insulating plate sections are sandwiched between battery cells, and the insulating walls are disposed between battery cell outer side-walls and metal bands to insulate the battery cells from the metal bands.