Method for determining the value of at least one first state of health parameter related to resistance (SOHR n+1, R n+1) of at least one accumulator of a battery, the method comprising the steps consisting in particular of: - performing a series of measurements of N samples (V k, I k, Ah k), with N ≥ 3, of at least voltage (V k), current (I k) and cumulative capacity (Ah k), at the terminals of said accumulator, when said accumulator is charged or discharged; - creating a minimization loop by varying a current value of the first parameter (SOHR step, R step) of the accumulator from a determined initial value (SOHR n, R n), comprising the following steps: (i) computing N estimated values of a second parameter (SOC k) relating to the state of charge of the accumulator from the current value of the first parameter (SOHR step, R step) and respectively from said N samples (V k, I k, Ah k); (ii) computing N theoretical values of the second parameter (SOC k,theoretical); (iii) varying the current value of the first parameter (SOHR step, R step), repeating the preceding computation steps for each variation of said current value of the first parameter (SOHR step, R step), and determining the value of the first parameter (SOHR n+1, R n+1) as being the current value of the first parameter (SOHR step, R step) which minimizes the difference between the estimated values (SOC k) and the theoretical values (SOC k,theoretical) of the second parameter. - performing a series of measurements of N samples (V k, I k, Ah k), with N ≥ 3, of at least voltage (V k), current (I k) and cumulative capacity (Ah k), at the terminals of said accumulator, when said accumulator is charged or discharged; - creating a minimization loop by varying a current value of the first parameter (SOHR step, R step) of the accumulator from a determined initial value (SOHR n, R n), comprising the following steps: (i) computing N estimated values of a second parameter (SOC k) relating to the state of charge of the accumulator from the current value of the first parameter (SOHR step, R step) and respectively from said N samples (V k, I k, Ah k); (ii) computing N theoretical values of the second parameter (SOC k,theoretical); (iii) varying the current value of the first parameter (SOHR step, R step), repeating the preceding computation steps for each variation of said current value of the first parameter (SOHR step, R step), and determining the value of the first parameter (SOHR n+1, R n+1) as being the current value of the first parameter (SOHR step, R step) which minimizes the difference between the estimated values (SOC k) and the theoretical values (SOC k,theoretical) of the second parameter. (i) computing N estimated values of a second parameter (SOC k) relating to the state of charge of the accumulator from the current value of the first parameter (SOHR step, R step) and respectively from said N samples (V k, I k, Ah k); (ii) computing N theoretical values of the second parameter (SOC k,theoretical); (iii) varying the current value of the first parameter (SOHR step, R step), repeating the preceding computation steps for each variation of said current value of the first parameter (SOHR step, R step), and determining the value of the first parameter (SOHR n+1, R n+1) as being the current value of the first parameter (SOHR step, R step) which minimizes the difference between the estimated values (SOC k) and the theoretical values (SOC k,theoretical) of the second parameter.