Device for interfacing between a battery management system and groups of battery cells including at least one set of local units and at least one global unit connected to the local units of said at least one set and including means for connection to a battery management system, each local unit of said at least one set being configured to be associated with a group of battery cells, - each local unit including a first comparison module configured to compare a parameter (Vcell, T a) relative to an associated group of cells to a first setting value (A1, At1), said first setting value (A1, At1) coming from said at least one global unit, and to generate an output signal representative of the result of said comparison, and - said at least one global unit being configured to receive said first setting value (A1, At1), said interface device being characterised in that said at least one global unit includes an electronic module having an operating parameter (Tosc) having a global value that is a function of the output signals coming from said local units of said at least one set, said global value being representative of the number of groups of cells of which said comparison results indicate that the value (Vcell, T a) of said parameter relative to an associated group of cells is greater than said first setting value (A1, At1), or of the number of groups of cells of which said comparison results indicate that the value of said parameter (Vcell, T a) relative to an associated group of cells is less than said first setting value (A1, At1); - said electronic module of the global unit including an oscillator circuit, said operating parameter being the period of oscillation (Tosc) of said oscillator circuit, each output signal coming from said local units of said at least one set being connected to said oscillator circuit via an output capacitor (Cso), so that said output capacitor (Cso) is connected in parallel with an oscillator capacitor (Co) of said oscillator circuit or disconnected according to said output signal. - each local unit including a first comparison module configured to compare a parameter (Vcell, T a) relative to an associated group of cells to a first setting value (A1, At1), said first setting value (A1, At1) coming from said at least one global unit, and to generate an output signal representative of the result of said comparison, and - said at least one global unit being configured to receive said first setting value (A1, At1), said interface device being characterised in that said at least one global unit includes an electronic module having an operating parameter (Tosc) having a global value that is a function of the output signals coming from said local units of said at least one set, said global value being representative of the number of groups of cells of which said comparison results indicate that the value (Vcell, T a) of said parameter relative to an associated group of cells is greater than said first setting value (A1, At1), or of the number of groups of cells of which said comparison results indicate that the value of said parameter (Vcell, T a) relative to an associated group of cells is less than said first setting value (A1, At1); - said electronic module of the global unit including an oscillator circuit, said operating parameter being the period of oscillation (Tosc) of said oscillator circuit, each output signal coming from said local units of said at least one set being connected to said oscillator circuit via an output capacitor (Cso), so that said output capacitor (Cso) is connected in parallel with an oscillator capacitor (Co) of said oscillator circuit or disconnected according to said output signal.