How to construct a battery management system

Assuming you are tasked with designing a monitor circuit for a new, battery-based power system, what strategies would you adopt to optimize the cost and manufacturability of the design? The initial consideration would be to determine the preferred structure of the system and the location of the battery and related electronic components. Once the basic structure is clear, the next issue that must be considered is the trade-offs of the circuit topology, such as how to optimize the communication and interconnection of the final product.

The battery's form factor will have a significant impact on the power system architecture. Will a large number of small cells be used to fit into a complex-shaped battery module (or pack)? Or will a large-form factor be used, limiting the number of cells due to weight issues or causing other size constraints? This is perhaps the area with the most design variables, as new battery forms continue to be introduced and efforts are made to make the battery module or pack more consistent with the overall product concept when integrated into the product. For example, in the case of an automotive design, the batteries may end up being dispersed in certain spaces on the vehicle that would be inefficiently used without the batteries.

Another consideration is the interconnection of test signals and/or telemetry signals between the battery (or modular battery pack), the battery management system (or its subsystems), and the final application interface. In most cases, a housing can be built to integrate some of the data acquisition circuitry in the battery module or battery pack so that if it needs to be replaced, important information such as production ID, calibration, usage specifications, etc. can be taken with the replaceable component. This type of information may be useful to the battery management system (BMS) or service equipment, and minimizes the number of high-voltage rated wires required in the wiring harness.