Abstract: A method to determine if at least one electrochemical cell is in a late-life stage of a life of the at least one electrochemical cell is provided. the method includes monitoring a voltage of the at least one electrochemical cell while powering at least one load; and determining a lowest voltage of the at least one electrochemical cell measured while powering the at least one load.

Abstract: The method and apparatus of the present invention increases the color fidelity and precision for controlling a plurality of cartridges that emit an extremely wide variety of colored ink droplets from twelve (12) high resolution ink jet print cartridges, or pens, onto unique printing substrates during print operations in a large format digital print engine. The present invention provides an automated method of creating customized, ink and media-dependent color transforms to enable optimized printing operations. In the preferred embodiment, a charge coupled device (CCD) illuminated by an array of carefully chosen light emitting diodes (LED) is used to generate color coordinates of each of a plurality of colored patches printed on a printing substrate. The LED array provides a source of illumination upon a portion of a printed substrate within the field of view of a CCD/lens assembly that covers approximately the 400 to 700 nanometer wavelength of light (the “visible spectrum”).