Method for determining an ageing function of an accumulator

A method for determining an ageing function of an accumulator, or of a group of accumulators, the ageing function representing a variation in the capacity or resistance of the accumulator, or of the group of accumulators, as a function of variables representative of the operation of the accumulator, the method comprising:

• a) carrying out a plurality of experimental cycles of charging and discharging at least one test accumulator representative of the accumulator or of the group of accumulators, each cycle being parameterised by accumulator operating parameters that vary as a function of time during the various cycles;
• b) during the charging and discharging cycles, at various measurement times, determining experimental data comprising a value of each variable parameter;
• c) on the basis of the experimental data resulting from b), determining the ageing function;
• wherein:
• b) comprises determining the state of charge and a depth-of-discharge value, at various measurement times of a given cycle, the depth of discharge value at each measurement time being determined from a difference between the state of charge at the measurement time and a state of charge at a preceding measurement time;
• in c), the variable parameters comprise at least the state of charge and a depth of discharge, such that, following c), the variables of the ageing function comprise at least the state of charge and the depth of discharge.