Patent ID: 7880444

Claim:
Process for the balanced charging of n cells, with n≧2, constituting a lithium ion or lithium polymer battery and associated in series, each of the cells being comprised by one or several elements mounted in parallel in the battery, the process comprising, for each charging operation, providing continuously or cyclically, from an instant (t 1 ) subsequent to the onset of the charging operation to the end or anticipated interruption of this operation, a surveillance of the levels of charge of the different cells, and carrying out, as a function of the mentioned evaluation of said charge levels, either a uniform supply of all the cells, or a balancing of said charge levels of said cells by supplying these latter in a differentiated manner as a function of their current levels of charge; triggering for each cell of the battery, one after the other, in a sequential manner, for a fractional portion of the total charge time of the battery, sequences comprising a refreshed evaluation of the level of the charge of the cell in question, followed, as a function of its level of charge and with respect to all the levels of charge of the other cells of the battery, a uniform or differentiated supply, this according to a repeating cycle from the instant (t 1 ) and throughout the following course of the operation of charging; wherein execution of the following operations is under the management of a digital processing unit from the instant t 1 : evaluation of the quantity of energy stored in each cell by measuring a parameter indicative of said quantity; comparative analysis of the different evaluated quantities of energy or of the different values of the measured parameter for each cell; determination of the cell tardiest to charge and of the cell or cells the most advanced in charging; supplying the different cells mounted in series in a uniform manner or with the limitation of charging current for the cells other than the tardiest or for the cell or cells most advanced in charging, by derivation of all or a portion of said current at the level of this or these latter; and sequential repetition of the different mentioned operations obtaining an end condition of charge of the battery or the detection of a fault, of a dysfunction or an exceeding of an admissible threshold value.