A method and apparatus for measuring and analyzing electrical or electrochemical systems

A method and apparatus for creating a time-varying electrical excitation, delivering it to a system comprising at least one electronic or electrochemical element, and measuring and analyzing a time-varying electrical response developed within the system in response to the excitation. The response signal, and optionally the excitation signal, are sampled in a synchronous manner, and the sampled values are analyzed to determine various characteristics of the system, including State of Charge and State of Health. Additional analysis may be performed to: identify specific system defects; identify and quantify time-dependent processes; and, obtain values for elements of an equivalent electric circuit model. The method and apparatus may serve both as a measurement system as well as a control sub­system, and may be configured to operate in either an open-loop or closed loop manner. Furthermore, the method and/or apparatus may be used in conjunction with a power control system such as an electrical/electrochemical system test device, a battery charger, a battery conditioner, or a battery backup system or uninterruptible power supply. Alternate embodiments of the technique may be achieved by integration directly within a chip or chipset.