Battery charger with enhanced charging and charge measurement processes

Abstract

A battery is rapidly charged utilizing a bipolar waveform (,). The voltage, current, duration and frequency parameters of the bipolar waveform are selected to perform a number of actions: enhancing the mixing action at the battery electrodes; measuring the battery's capacitance, condition, and level of impedance; modifying the mass transport process inside the battery; and reducing the concentration of the diffusion layer, the polarization concentration, and the overpotential. This reduces internal heat generation by providing for more efficient ion transport, reduced concentration gradients, and increased diffusion rates and intercalation speeds. A bipolar waveform can be in the form of sine waves, or other wave shapes. A charge pulse (,) is preferably followed by a small technical rest period (,), after which a discharge pulse (,) is applied followed, in turn, by a rest period (,). The bipolar waveform (,) is superimposed on one or more of the above. A second discharge pulse (,) is then applied followed by another rest period (,). A second bipolar waveform (,) is superimposed on either the second discharge pulse (,) or the second rest period (,). The second bipolar waveform (,) allows a measurement of the battery capacitance to be obtained and an evaluation of the charge of the battery to be derived. The charge cycle is repeated until a measured battery parameter attains a desired value indicative of a charged battery.