Patent ID: 7719231

Claim:
Process for the balanced charging of a lithium ion or lithium polymer battery comprised of a series of n different cells ( 1 ), with n>2, each cell being comprised of elements mounted in parallel, said process comprising the steps of: continuously providing, from an onset of a charging operation of the battery ( 2 ) and throughout the charging operation, a surveillance of levels of charge of the different cells ( 1 ); carrying out, as a function of the surveillance of said charge levels, one of i) a uniform supply of all the cells ( 1 ), and ii) a balancing of said charge levels of said cells ( 1 ) by supplying said cells in a differentiated manner as a function of said cell's current levels of charge; triggering for each cell ( 1 ) of the battery, one cell after another cell in a sequential manner, for a fractional portion of the total charge time of the battery ( 2 ), sequences comprising a refreshed evaluation of the level of the charge of the cell ( 1 ) in question, followed, as a function of the cell's level of charge and with respect to all the levels of charge of the other cells ( 1 ) of the battery, a uniform or differentiated supply, according to a repeating cycle throughout the charging operation; and executing, from the beginning of the charging operation, the following operations under the management of a digital processing unit ( 3 ): A) evaluation of the quantity of energy stored in each cell ( 1 ) by measuring a parameter indicative of said quantity; B) comparative analysis of the different evaluated quantities of energy or of the different values of the measured parameter for each cell ( 1 ); C) determination of the cell ( 1 ) tardiest to charge and of the cell or cells ( 1 ) the most advanced in charging; and D) supplying the different cells ( 1 ) in one of i) a uniform manner and ii) with the limitation of charging current for the cells ( 1 ) 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 a limited level; with a sequential repetition of the operations A), B), C), and D) obtaining one of i) an end condition of charge of the battery ( 2 ) and ii) a detection of a fault, of a dysfunction or an exceeding of an admissible threshold value.