Abstract: Methods and systems for constructing a battery, the battery including at least two energy storage sections connected in parallel to a common module power bus, the energy storage sections including at least one battery cell and at least one section disconnect device capable of disconnecting the at least two energy sections from the module power bus, and, a section protection device to control the section disconnect device based on data from the energy storage sections. In an embodiment, the battery can include at least two battery modules connected in series using an interlock signal, where the battery modules include a module protection device having an interlock signal controller and fault logic for controlling the interlock signal controller, such that the modules can control the interlock signal and hence a disconnect device that receives the interlock signal and is connected between the modules and a load and/or charger.

Abstract: A large battery pack of specified voltage and capacity can be assembled from a plurality of identical small cells by dividing the specified capacity by a nominal battery module capacity to determine a desired number of parallel modules to be provided, dividing the nominal battery module capacity by a nominal cell card capacity, to determine the number of cell cards required in each module, connecting the call cards in parallel to a common buswork to form the battery module, and connecting the modules in parallel to obtain the specified battery pack capacity and in series to obtain the specified battery pack voltage Protection circuitry can be implemented at the module level, by disconnecting one or more modules or the entire battery pack if a fault at the module level is identified; at the cell card level, by disconnecting a cell card if a cell within it is determined to be faulty; and/or internally, in each cell.