Provided are a battery regulation system and method and an electrical device thereof. The battery regulation system is applied to a vehicle comprising a first motor and a second motor; and the battery regulation system comprises a battery module, a regulation module, and a control module, wherein the regulation module is electrically connected to the battery module and the control module; the battery module comprises a first battery and a second battery, the first battery and the second battery being connected in series, wherein the first battery is used for powering the first motor and the second battery is used for powering the second motor; and the control module is used for controlling the regulation module to regulate the states of charge of the first battery and the second battery when the states of charge of the first battery and the second battery are not consistent.