The invention discloses charging control method and
system of a
lithium ion battery pack, wherein the method comprises the following steps of: charging the
lithium ion battery pack through a constant-current value after starting charging, monitoring the
voltage of each
monomer battery in real time in the whole charging process, and carrying out equalizing charging on a battery with the
voltage lower than a mean value by taking the energy from the battery with the
voltage higher than the mean value; when the highest voltage of the
monomer battery reaches an upper
limit value, converting a charging mode, and carrying out constant-voltage charging on the
battery pack through the
current voltage value of the battery pack; and when the highest voltage of the
monomer battery is lower than the resetting value of the preset upper
limit value, gradually increasing the charging voltage through preset voltage step length
delta V until the voltage of the
lithium ion battery pack reaches a preset constant-voltage value, and when the charging current of the
lithium ion battery pack is decreased to a preset charging current end value, ending the charging. The
system comprises a battery
management system, charging equipment and an equalizing unit. Through the invention, the actual charging capacity of the
lithium ion battery pack can reach the designed capacity under the condition of ensuring no overcharging.