METHOD AND DEVICE FOR ESTIMATING THE STATE OF HEALTH OF AN EXCHANGEABLE RECHARGEABLE BATTERY

A method for estimating the state of health of an exchangeable rechargeable battery. The method includes: i. determining a remaining capacity of the battery during a charging operation, in such a manner, that a first charging value is ascertained by measuring an open-circuit voltage, as long as no charging current or only a minimal charging current is flowing; at least one further charging value is ascertained by measuring the charging current in specific time intervals, until the charging operation is completed; and a sum of the ascertained charging values is calculated; ii. determining a remaining performance of the battery during the charging operation in such a manner, that after a predefined battery voltage is reached, the charging current is briefly changed, and the respective battery voltage is measured; and an impedance of the battery is calculated from the quotient of the difference of the measured charging currents and battery voltages.