NOVELTY - A battery has working electrodes spaced by at least one separator and individually electrically connected with positive terminal (810) and negative terminal (820), at least one reference electrode (840), and a cylindrical can (830) housing the working electrodes and the reference electrode. The can is electrically isolated from the working electrodes yet electrically connected to the reference electrode to provide at least a terminal for the reference electrode. The reference electrode can interface with a battery management system for battery charging and or monitoring state of charge.    USE - Battery e.g. for power supply in plug-in hybrid electric vehicle. Uses include but are not limited to a lithium ion battery, a cylindrical battery, a prismatic battery, and pouch battery (All claimed), and secondary battery e.g. lead acid battery, alkaline manganese battery, nickel cadmium battery, nickel metal hydride battery. Can also be used in portable electronics products e.g. wireless communications devices and laptop computers, power tools, electric vehicles including hybrid electric vehicles and all-electric vehicles, back-up power systems, energy storage for power generation devices such as solar or wind collectors or fuel cells or fuel-burning power sources.    ADVANTAGE - Inclusion of reference electrode into battery without needing additional port in cell can or capping lids for reference electrode material simplifies battery cell design as well as improving state of charge and state of health monitoring over battery lifetime. Use of reference electrode in battery also meets operating requirements that hybrid electric vehicle, plug-in hybrid electric vehicle, and electric vehicle systems have in terms of power, charge/discharge rate, cycle life, and calendar life, and provides information needed to monitor and optimize complex battery systems utilizing cells with tight operating parameters found in plug-in electric vehicles.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a method of supplying power;    (2) a lithium ion battery system;    (3) a method of avoiding lithium plating in a lithium ion battery;    (4) a method of minimizing charge time of a lithium ion battery by maximizing charge current applied at any particular state of charge during a charging event; and    (5) a method of detecting whether there is an electrical connection between a can and either terminal of a cell.    DESCRIPTION OF DRAWING(S) - The drawing shows the perspective view of a cylindrical cell with a reference electrode.    Positive terminal (810)    Negative terminal (820)    Can (830)    Reference electrode (840)    Gaskets (850)