IN-VEHICLE SYSTEM, METHOD, AND NON-TRANSITORY STORAGE MEDIUM

An in-vehicle system includes a first battery and a second battery respectively connected to a first load and a second load, a relay that connects the two batteries in parallel, and a processor configured to control turn-on and turn-off of the relay to control a state of electric power supply from the first and second batteries to the first and second loads, detect an abnormality in the first and second batteries, and determine a difference between physical quantities of the two batteries. The processor is further configured to, when detecting the abnormality in the first or second battery, turn off the relay, and when no longer detecting the abnormality in the first and second batteries after the relay is turned off, turn on the relay when the processor determines that the difference between the physical quantities of the two batteries satisfies a predetermined condition.