US Patent 11342760 Electrical device for parallel connected batteries

An electrical device having a plurality of parallel-connected built-in rechargeable batteries includes a power supply terminal and a charging circuit. The power supply terminal receives electrical power supplied from the outside of the electrical device. The charging circuit executes charge control so as to charge the plurality of rechargeable batteries using the electrical power supplied from the outside. During the execution of the charge control, the charging circuit interrupts charging of any one of the plurality of rechargeable batteries in accordance with a magnitude of a charging current flowing to each of the plurality of rechargeable batteries.