A process to evaluate the condition of the cells (Ci) of a battery that comprises a plurality of serially connected cells (Ci), wherein the process comprises the following steps: a) during a loading or unloading stage of the battery, measure the voltage Ui at the terminals of each cell (Ci); b) when a first cell (Ci_lim) reaches a preset end-of-loading or end-of-unloading condition, stop the battery loading or unloading and store, for each cell (Ci) the voltage Ui of the cell at the end of the loading or unloading stage of the battery; c) calculate the charge Qtot extracted from the battery or injected into the battery between the start and the end of a complete loading phase or of a complete unloading phase of the battery, and deduce the value QCi_lim representative of the capacitance of the first cell; d) calculate for each one of the other cells of the battery an interpolation coefficient C_interp_i from a value C_rate representative of the loading or unloading regime of the battery and from the end-of-loading or end-of-unloading voltages Ui that were stored at stage b); and e) calculate, for each one of the other cells of the battery, from the value QCi_lim of stage c) and from the interpolation coefficient C_interp_i that was calculated for the cell at stage d), the value QCi representative of the capacitance of the cell, wherein, for each one of the other cells (Ci), the interpolation coefficient C_interp_i calculated at the step d) is a function of the voltage Ui of the cell as stored at step b), of the C_rate value, of a value Umin that is defined as the lowest voltage of the set of voltages Ui stored at step b), of a value Umax that is defined as the highest voltage of the set of voltages Ui stored at step b), and of a value Umoy that is defined as the average of the set of voltages Ui stored at step b), and wherein, for each cell (Ci), the interpolation coefficient C_interp_i calculated at step d) is defined as: C _ interp _ i = K + B ∗ D ∗ C + B ∗ D ∗ E − B ∗ A / K where A, B, C, D, E and K are parameters defined as: K = Umoy 2 ∗ 1 + C _ rate / 2 ∗ C _ rate A = Umax − Ui B = Ui − Umin C = Ui / Umin D = Ui / Umax E = Umax − Umin / Ui a) during a loading or unloading stage of the battery, measure the voltage Ui at the terminals of each cell (Ci); b) when a first cell (Ci_lim) reaches a preset end-of-loading or end-of-unloading condition, stop the battery loading or unloading and store, for each cell (Ci) the voltage Ui of the cell at the end of the loading or unloading stage of the battery; c) calculate the charge Qtot extracted from the battery or injected into the battery between the start and the end of a complete loading phase or of a complete unloading phase of the battery, and deduce the value QCi_lim representative of the capacitance of the first cell; d) calculate for each one of the other cells of the battery an interpolation coefficient C_interp_i from a value C_rate representative of the loading or unloading regime of the battery and from the end-of-loading or end-of-unloading voltages Ui that were stored at stage b); and e) calculate, for each one of the other cells of the battery, from the value QCi_lim of stage c) and from the interpolation coefficient C_interp_i that was calculated for the cell at stage d), the value QCi representative of the capacitance of the cell, wherein, for each one of the other cells (Ci), the interpolation coefficient C_interp_i calculated at the step d) is a function of the voltage Ui of the cell as stored at step b), of the C_rate value, of a value Umin that is defined as the lowest voltage of the set of voltages Ui stored at step b), of a value Umax that is defined as the highest voltage of the set of voltages Ui stored at step b), and of a value Umoy that is defined as the average of the set of voltages Ui stored at step b), and wherein, for each cell (Ci), the interpolation coefficient C_interp_i calculated at step d) is defined as: C _ interp _ i = K + B ∗ D ∗ C + B ∗ D ∗ E − B ∗ A / K where A, B, C, D, E and K are parameters defined as: K = Umoy 2 ∗ 1 + C _ rate / 2 ∗ C _ rate A = Umax − Ui B = Ui − Umin C = Ui / Umin D = Ui / Umax E = Umax − Umin / Ui