Method and apparatus for measurement of electrochemical cell and battery impedances

摘要

A battery's impedance is measured by a technique that normally uses a current divider network which is connected to the battery. The circuit used according to this technique has a current generator (53) producing a regulated current signal (Ii) and has one or more sensing impedances (Zs) which are normally positioned electrically parallel, or in some alternate embodiments in series, with the battery. A DC-blocking capacitor prevents the battery voltage from draining into the one or more sensing impedances (Zs). A magnetic field sensor or comparable device measures the magnitude and/or phase of current passing through the sensing impedances. Substitution of a number of calibrated impedances into the circuit in place of the battery permits an initial mathematical computation of the battery's impedance utilizing this technique. Thereafter battery impedances can be computed with the current without using calibrated impedances.