Patent ID: 7425832

Claim:
An electrochemical system comprising a plurality of cells; a current supply/draw means for superimposing modulated current values through the plurality of cells, wherein the current supply/draw means comprises a modulator, wherein the modulator comprises a control device and a modulated current generator, wherein the control device is operable to control the modulated current generator to superimpose the modulated current values in burst time periods for high frequency resistance measurement, with a rest time periods between the burst time periods of no superimposition of modulated current values; an external load connected to the plurality of cells in parallel with the current supply/draw means for drawing a DC current from the plurality of cells wherein the DC current is drawn from the plurality of cells during both the rest time period and the burst time periods; a measuring device including a plurality of inputs connected across the plurality of cells to generate signals indicative of voltage and current characteristics of the plurality of cells; and, a controller for controlling at least one system operating condition based on to the voltage and current characteristics received from the measuring device, the controller being connected to the measuring device.