Hardware

The hardware for the battery management system will fall into two types:

**Master and Slaves**: a slave will monitor and control a sub-set/module of cells and communicate back to the master.

**Centralised Control Unit**: long leads are required to connect the central control unit to every cell in the pack.

Cell Management Controller

The “Slave” controller that is localised to a group of cells.

Communication Architectures

Battery communication is typically split into three functional zones:

Cell Sensing Layer (intra-module)
Backbone/System Layer (inter-module)
External Interface Layer (BMS to vehicle/grid).

Chipsets

Four semiconductor giants dominate the modern BMS architecture, each leveraging distinct technological philosophies and manufacturing advantages to capture market share:

Texas Instruments (TI)
NXP Semiconductors
Analog Devices (ADI)
Renesas Electronics

Overview of BMS Chipsets: as battery pack costs decrease, advanced BMS intelligence is becoming viable in mid-range vehicles and smaller industrial devices that previously could not justify the integration costs. Manufacturers are now focusing on a “platform approach” where a single chipset architecture can scale from 48V mild hybrids to 800V/1500V grid-scale storage systems. This modularity is essential for managing the diverse needs of the automotive (50% market share), energy storage (20%), and consumer electronics (15%) segments.

Hardware Suppliers

There are a number of suppliers of BMS worldwide who design and build systems for single cell all the way up to complex managed BMS systems that can control very large grid based battery systems.

Harness

The wiring system that connects the BMS sections and sensors together.

Flexible Printed Circuits (FPCs) are the hidden nervous system of high-voltage batteries, yet their reliability is often overlooked.

For long-term reliability, FPC design deserves as much focus as chemistry and cooling.

Signal Pathway: Every cell voltage and thermistor channel depends on the FPC.
Space & Weight Efficiency: Slim, lightweight alternatives to bulky wiring harnesses.
High-Voltage Environment: Subjected to constant electrical, thermal, and vibration stress.
Single Point of Failure: A single crack or loose connector can disable a full module.

Temperature Measurement

Normally limited a few channels and points over a complete battery pack. The trade-off between physical channel count and coverage is explored further in How Many Temperature Sensors are Required?, while virtual temperature sensors and a comparison of physical sensing technologies cover ways to fill in the gaps between measured points.

Voltage Measurement

Denso claim that their individual cell voltage measurement has an error within 3mV. Achieving that kind of accuracy in practice depends heavily on the sensing wiring itself — see Seebeck error for one subtle source of measurement drift.