Interconnection

An interconnection for a battery comprising a plurality of cells, the interconnection comprising:

• an electrically insulating substrate having a first face and a second face;
• a heat sink on the first face of the substrate;
• a flow of fluid in proximity to the heat sink;
• a layer of electrically conducting material on the second face of the substrate, said layer of electrically conducting material providing a plurality of cell-receiving regions for direct electrical connection with the plurality of cells, wherein the plurality of cell-receiving regions are arranged to allow connection to one or more of the plurality of the cells independently of connection to others of the plurality of cells, and
• electrical circuitry mounted on the second face of the substrate and configured to control a state of charge and a temperature of each of the one or more of the plurality of the cells independently of others of the plurality of cells,
• wherein the electrical circuitry to control the state of charge and the temperature of each of the one of more of the plurality of cells comprises two or more resistors and one or more temperature gauges mounted on the second face of the electrically insulating substrate, and wherein each resistor is positioned at a location proximate to one of the plurality of cell-receiving regions and generates heat when a current is passed through the each resistor, the heat being conducted to the proximate cell-receiving regions, and
• wherein each of the one or more temperature gauges is positioned at a location proximate to one or more of the plurality of cell-receiving regions, and the electrical circuitry controls the current passed through each resistor and the flow of fluid to the heat sink.