US Patent 11411421 Control device and method for charging a rechargeable battery

A control device for controlling charging of a rechargeable battery, the control device including a rechargeable dummy cell, a first circuit configured to charge the battery and the dummy cell, and a second circuit configured to measure the open circuit voltage of the dummy cell. The control device is configured to: determine the open circuit voltage of the dummy cell by using the second circuit, and determine the maximum capacity increment of the battery, which is to be charged until full charging, based on the determined open circuit voltage of the dummy cell. Also, a corresponding method of controlling charging of a rechargeable battery.