RE:Update on PatentFrom the Patent Document:
Abstract
A battery control system includes a plurality of battery cells that are separately controllable as units of individual cells or groups of cells. Each controllable unit may be switchably activated or deactivated in the overall battery circuit, and one or more conditions of each controllable unit may be individually measured. Various techniques are disclosed for operating the battery control system to optimize or improve system performance and longevity
One aspect of this disclosure is directed to facilitating charging different battery cells in the same string at different current levels, which in turn enables the use of battery cells at different state of charge (SoC) and state of health (SoH). This capability is applicable to a variety of battery-utilization and battery-charging applications. One such application is a battery-based an energy storage system for powering equipment, homes, buildings, or other consumers of electrical power who have traditionally taken power from a power grid. Other applications include energy storage for power generation facilities to provide increased capacity in peak periods, or during periods when renewable power sources are less available (e.g., at night or during dark/overcast weather conditions in the case of solar power, during periods of low wind or dangerously high winds in the case of wind power). Other applications include vehicles (e.g., road, rail, sea, air) that are battery-powered or hybrid-powered and thus carry batteries onboard. In some related applications, energy storage systems utilizing at least some of the disclosed techniques can effectively make use of second-life battery cells, which ended their prior service due to SoH. Certain implementations may achieve a comparable SoC among all cells and minimize SoH deterioration for those cells, thereby extending their service life. According to some embodiments, as detailed below, cells may be switched in and out based on their SoC or SoH. According to one aspect, all cells are maintained at a same SOH so that an entire rack of cells can be changed simultaneously.