Patent ID: 8148950
Filing Date: 2012-04-03
Classification: H02J

Abstract:
1. A constant-voltage and constant-current lithium-ion rechargeable battery charging method comprising: a first charging step of detecting, at a current that is currently applied to a battery to be charged, a temperature rise gradient of the battery, predicting a battery temperature when the battery will be charged to a first predetermined capacity based on the detected temperature rise gradient, controlling a charging current based on the predicted temperature, and charging the battery to the first predetermined capacity at a current that results in a temperature of the battery that is lower than a predetermined temperature; and, after the battery is charged to the first predetermined capacity, a second charging step of detecting, at a current that is currently applied to the battery to be charged, a temperature rise gradient of the battery, predicting a battery temperature when the battery will be charged to a second predetermined capacity based on the temperature rise gradient, controlling a charging current based on the predicted temperature, and charging the battery to the second predetermined capacity at a current that results in a temperature of the battery that is lower than the predetermined temperature at the second predetermined capacity, wherein the second predetermined capacity is higher than the first predetermined capacity, wherein, during the charging of the battery to the first predetermined capacity in the first charging step, the battery temperature is predicted as the battery temperature at the first predetermined capacity on the condition that the battery will be charged to the first predetermined capacity, and wherein, during the charging of the battery from the first predetermined capacity to the second predetermined capacity in the second charging step, the battery temperature is predicted as the battery temperature at the second predetermined capacity on the condition that the battery will be charged to the second predetermined capacity.