A Modular, Scalable Battery Management System


Grid Battery Controller

Aggregates multiple stacks and manages them as a single battery. Provides unified control over Modbus TCP (Ethernet) and acts as a data analytics gateway. Supports both low- and high-voltage applications.

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  • Collects pack-level voltage, temperature, and current statistics for all cells, SOC and SOH, system-wide faults, warnings, and battery pack diagnostics for the entire battery.
  • Provides a single entry point to all measurement and control points in the BMS.
  • Ensures that measurements, control signals, and other data are propagating properly through the entire system.
  • Streams real-time data to external servers for analytics and trend data capture.
  • Multi-socket Ethernet interface allows concurrent operation of both local and remote operator panels, data analytics streaming, and Modbus TCP inverter control.
  • MESA Draft 3 compliant Modbus TCP for connection to power conversion systems.
  • Pushes firmware and configuration updates to all BMS modules across entire battery.

Power Interface

One used in each high-voltage battery stack. Measures stack current, powers other high-voltage BMS modules. Includes built-in coil drivers to control contactors.

  • Provides operating power for the system, sourced from the battery stack or sourced from a 24 VAC/VDC input, which allows full functionality even with fully discharged battery cells.transparent-power-interface-web_0.png
  • Monitors stack current via an external temperature-compensated inline current shunt for high accuracy.
  • Monitors battery stack voltage.
  • External equipment interlock connector provides contactor enable and E-stop contactor disconnect functions.
  • LEDs provide Power, Activity, and Fault status.
  • Includes coil drivers for 4 contactors; 24 VDC provided for contactor coils, optional external coil power input for voltage flexibility.

Stack Controller

One used in each high-voltage battery stack. Connects to Cell Interfaces to manage balancing and provide stack management. Measures State of Charge and State of Health at both the cell and stack levels. Communicates with external systems via Modbus TCP (Ethernet), Modbus RTU (RS-485), or CAN.

  • Master controller for the BMS stack.transparent-stack-controller-web_0.png
  • Communicates external systems via Modbus TCP (Ethernet), Modbus RTU (RS-485), or CAN bus.
  • Provides State of Charge and State of Health tracking.
  • Supports firmware upgrades via Ethernet.
  • Includes Link Bus interface to Cell Interface module(s).
  • Includes Stack Bus interface to Power Interface module.
  • LEDs provide Power, Activity, and Fault status.

Stack Switchgear (SSG)

One SSG is used per stack. Includes the Stack Controller (SC) and Power Interface (PI) modules required to manage the stack. Can provide a range of stack management support and include battery management modules, fuses, contactors, bus bars, current shunts, pre-charge circuits, e-stop, communications, and other requirement-specific software and hardware components.

  • Connects and disconnects a battery stack to the DC Bus of the ESS in response to requests from system controllers. Will also report the resulting capacity change to the PCS and other energy management systems.Stack Switchgear
  • Provides battery stack terminal connections as well as communications I/O for other ESS controllers.
  • Receives voltage and temperature data from Nuvation Energy’s Cell Interface BMS modules (sold separately) that are connected to the cells. Provides cell balancing commands to those modules during the charge cycle.
  • Calculates State of Charge (SoC) and Depth of Discharge (DoD) and uses voltage and temperature data from the BMS to determine safe current thresholds. Provides those current thresholds to the power conversion system, which uses this information to regulate charge and discharge currents.
  • Executes safety disconnect commands from the BMS to protect the battery if cell performance thresholds (i.e. temperature, voltage, SoC, DoD) have been exceeded. Also includes over-current as well as short-circuit protection.
  • Can control battery module cooling fans in response to temperature data from the BMS.

Cell Interface

Used in both low- and high-voltage battery stacks. Connects directly to cells (12- and 16-channel models available). Measures voltage and temperature, provides cell balancing. In a high-voltage battery stack, multiple CIs manage series-connected cells to reach voltages of up to 1250 VDC. For low-voltage applications, one CI can be added to a Nuvation Energy Low-Voltage BMS to increase the number of series-connected cells in a stack.

  • Used in both low- and high-voltage battery stacks.transparent-cell-interface-web_0.png
  • Measures voltage and temperature of each cell, provides cell balancing.
  • Connects directly to cells (12- and 16-channel models available).
  • Includes internal temperature monitoring of the module plus 8 external sensor inputs for the cells.
  • In a high-voltage battery stack, multiple CIs manage series-connected cells to reach voltages of up to 1250 VDC.
  • For low-voltage applications, one CI can be added to a Low-Voltage Battery Controller to increase the number of series-connected cells in a stack.
  • Stackable architecture supports using multiple Cell Interfaces to support hundreds of cells in series.
  • Galvanically isolated serial communications between Cell Interfaces and the Stack Controller protect the system from electromagnetic interference and enable floating battery architectures and highly accurate voltage readings.
  • Up to 80 VDC per Cell Interface.
  • Provides passive balancing up to 300mA.
  • Daisy chain architecture; no addressing switches to set.
  • LEDs provide Activity and Fault status.

Low-Voltage Battery Management System

The equivalent of a Power Interface, Stack Controller, and Cell Interface in one package for applications with a nominal voltage of up to 60 VDC. Will support the periodic peak voltages of up to 68 VDC that can occur during battery maintenance operations such as lead battery equalization. 12- and 16-channel models are available. Can manage additional cells in series by adding one Cell Interface. One Nuvation Energy Low-Voltage Battery Management System manages one stack. Multi-stack management is available by adding a Grid Battery Controller.

  • Supports 11-60 VDC. Will support the periodic peak voltages Low-Voltage Battery Controllerof up to 68 VDC that can occur during battery maintenance operations such as lead battery equalization.
  • Communicates with systems outside of the BMS via Modbus TCP (Ethernet), Modbus RTU (RS-485), or CAN bus.
  • 12- and 16-channel models are available.
  • Can manage additional cells in series by adding one Cell Interface.
  • One Nuvation Energy Low-Voltage BMS manages one stack.
  • Multi-stack management is available by adding a Grid Battery Controller.