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Battery Management System Block Diagrams

A battery management system is the brain of every EV pack and grid-scale energy storage system — it monitors cell voltages, balances charge, enforces safety limits, and communicates state-of-charge data to the host system. Mapping all these subsystems in a clear block diagram is the first step in any BMS design review. ChatDiagram generates BMS architecture diagrams from a description of your system.

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1 template
Block diagram Battery Management System
Battery Management System ArchitectureBattery Management System ArchitectureBattery Management SystemUse template →

Nothing close enough? Start from a blank block diagram → Describe it in one paragraph.

How to

How to use a block diagram template.

  1. 01Define the battery pack structure

    Describe the cell count, module arrangement, and chemistry: "96S2P Li-ion pack divided into 8 modules of 12 series cells each".

  2. 02Add sensing and measurement blocks

    Ask to include cell voltage monitoring (AFE IC), current sensing (Hall effect or shunt), and temperature sensing (NTC thermistors) per module.

  3. 03Show protection and balancing circuitry

    Request "passive cell balancing resistors, pre-charge relay, main contactors, and fuse protection" to map the safety architecture.

  4. 04Include the master controller and communication

    Ask for "a master BMS MCU computing SoC and SoH, communicating via CAN to the vehicle control unit and via SMBus to the charger".

  5. 05Export for design review

    Download as PNG or SVG to include in BMS design review presentations, patent filings, or system requirement documents.

FAQ

Questions about block diagram templates

What are the main functional blocks of a BMS?

Core BMS blocks are: cell monitoring (voltage, temperature, current), cell balancing (passive resistive or active charge shuttling), protection (overcurrent, overvoltage, undervoltage, short-circuit), state estimation (SoC, SoH, SoP), thermal management, and communication interface (CAN, LIN, SMBus).

What is the difference between passive and active cell balancing?

Passive balancing dissipates excess charge from high-SoC cells as heat through bleed resistors — simple but inefficient. Active balancing transfers charge between cells using inductors or capacitors — more complex but reduces energy waste.

Can I draw a master-slave BMS architecture for a large pack?

Yes. Ask for "a master-slave BMS with one master controller and four slave AFE boards, each managing 12 cells, communicating over an isolated CAN bus".

Does the diagram show the contactor and pre-charge circuit?

Yes. Ask to "include main positive and negative contactors and a pre-charge relay with resistor to limit inrush current" and the AI adds these power-path components.