Abstract: A method for determining an impedance of an electrically conducting device, such as a battery or a welded metal joint, includes applying a time-varying electric current to the electrically conducting device. The current varies at least between a first level and a second level. The current changes between the first level and second level within a time interval that is so short that a voltage response of the electrically conducting device exhibits a first local voltage extremum followed by a decay. An ohmic resistance voltage is adopted by the voltage response, when the first local voltage extremum has decayed. The method further includes acquiring the voltage response at least partially and determining an impedance of the electrically conducting device from the acquired voltage response.

Abstract: A method for determining an impedance of an electrically conducting device, such as a battery or a welded metal joint, includes applying a time-varying electric current to the electrically conducting device. The current varies at least between a first level and a second level. The current changes between the first level and second level within a time interval that is so short that a voltage response of the electrically conducting device exhibits a first local voltage extremum followed by a decay. An ohmic resistance voltage is adopted by the voltage response, when the first local voltage extremum has decayed. The method further includes acquiring the voltage response at least partially and determining an impedance of the electrically conducting device from the acquired voltage response.