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. <EOS>