BATTERY-STATE ESTIMATION DEVICE

摘要

At a first point in time, this battery-state estimation device obtains a first resistance value corresponding to a first open voltage for a lithium-ion secondary battery and a second resistance value corresponding to a second open voltage for said lithium-ion secondary battery, said second open voltage being higher than the first open voltage. At a second point in time that is different from the aforementioned first point in time, this battery-state estimation device obtains a third resistance value corresponding to the aforementioned first open voltage and a fourth resistance value corresponding to the aforementioned second open voltage. On the basis of whether a first change amount equal to the difference between the first resistance value and the third resistance value is larger or smaller than a second change amount equal to the difference between the second resistance value and the fourth resistance value, this battery-state estimation device determines the presence or absence of lithium deposition in the lithium-ion secondary battery.