Method and device for determining the actual capacity of a battery

US9400313B2 · kind B2 · utility

Assignee

• AUDI AG · DE

Inventors

• Alexander Barke · Ingolstadt, DE
• Rolf Naumann · Krefeld, DE

Key dates

• Filing date: May 17, 2013
• Grant date: Jul 26, 2016
• Expiry date: May 17, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/367
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and a device for determining the actual capacity of a battery uses a set of characteristic curves, wherein at the start of a discharge process the initial voltage of the battery, the magnitude of the discharge current and the temperature of the battery are determined. From this, by comparison with the data provided in the set of characteristic curves, a characteristic curve is selected and an initial state of the battery is determined. At the end of the discharge process, the final voltage of the battery is measured. The final voltage is compared, at the end of the discharge, with the voltage expected based on the selected characteristic curve and, in the event that the final voltage is smaller than the voltage expected based on the discharge process, it is determined that the actual capacity of the battery is smaller than the available capacity assumed at the start of the discharge process.