Patent ID: 9166418
Filing Date: 2015-10-20
Classification: B60L,H02J,Y02T

Abstract:
1. A battery system comprising: a first battery; a second battery connected in parallel to the first battery; a first relay that switches between a state of allowing and a state of prohibiting charging and discharging of the first battery; a second relay that switches between a state of allowing and a state of prohibiting charging and discharging of the second battery; a controller that controls the first relay and the second relay; and a voltage sensor that detects a voltage of each of the first and second batteries and outputs a detection result to the controller, wherein: the first battery is configured to be charged and discharged with a larger current than the second battery; the second battery has a higher storage capacity than the first battery; when the voltage of the second battery is lower than the voltage of the first battery, the controller allows charging of the second battery through the second relay while prohibiting charging of the first battery through the first relay until the voltage of the second battery reaches the voltage of the first battery; and the controller allows, when the voltage of the second battery reaches the voltage of the first battery, charging of the first battery through the first relay and charging of the second battery through the second relay.