polyester type the nature of the insulating substrate and that of the conducting sheet can be the subject of many implementation variants in particular the conducting area can be composed of a sheet of copper in addition according to the invention the interconnection system 100 is flexible as illustrated in the aforementioned figures this allows the torsion of the connection jumpers of the retention means 110 120 and 150 and a configuration in three dimensions of the interconnection system 100 referring now to fig6 a set of n energy storage cells is illustrated connected in series according to the invention each of the cells 1 to n is connected respectively to a circuit 10 to n 0 configured so as to propose a voltage measuring circuit with on off switching indicating the energy state of an individual cell and a diversion circuit for the current passing through each cell with on off switching depending on this energy state for an individual energy storage cell 2 a diversion circuit 20 is connected in parallel with the cell 2 a conductor 21 forms a current diversion path starting from a polar terminal 2 a of the cell 2 and leads to the monitoring means 300 of the energy storage assembly 200 in which it is connected to an on off switching means 23 this on off switching means 23.