Nuvation Energy NUVG5 User manual

Nuvation Energy G5 High-Voltage BMS
NUVG5 Product Manual
Document ID: NE-DS-011 | Revision: 1.0, 2023-05-19
BMS Software Version: G5 Faraday
© 2023 Nuvation Energy

Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê2
1.1. About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê2
2. Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê3
2.1. G5 Stack Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê5
2.2. G5 Cell Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê7
2.3. G5 BMS Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê8
2.3.1. Operator Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê8
2.3.2. G5 BMS Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê8
2.3.2.1. Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê9
3. Functional Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê10
4. Installation Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê12
4.1. Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê12
4.2. G5 Cell Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê13
4.2.1. Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê13
4.2.2. Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê14
4.2.2.1. Dimensions and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê14
4.2.2.2. Installation Location and Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê14
4.2.2.3. Mounting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê15
4.2.3. Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê16
4.2.3.1. Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê16
4.2.3.2. Connect the Cell Voltage and Temperature Cable . . . . . . . . . . . . . . . . . . . . . . . . Ê16
4.2.3.3. Connect the Link Bus Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê17
4.3. G5 Stack Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê18
4.3.1. Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê18
4.3.2. Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê19
4.3.2.1. Dimensions and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê19
4.3.2.2. Installation Location and Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê20
4.3.2.3. Mounting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê20
4.3.3. Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê25
4.3.3.1. Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê25
4.3.3.2. Ensure system is de-energized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê26
4.3.3.3. Ground the G5 Stack Switchgear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê26
4.3.3.4. Connect Power In and Fan Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê27
4.3.3.5. Connect control to General Purpose Input/Output (GPIO) cable . . . . . . . . . . . . . . Ê28
4.3.3.6. Connect Ethernet cable to external computer . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê28
4.3.3.7. Connect Link Out cable to G5 Cell Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê29
4.3.3.8. Set the Config Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê30
4.3.3.9. Connect Battery Stack and DC Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê30
4.3.3.10. Energize G5 Stack Switchgear and Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê32
4.4. G5 Operator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê33
4.4.1. Download and Install the G5 Operator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê33
4.4.2. Connect to the G5 Operator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê33

4.5. First Power-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê36
5. Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê37
5.1. Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê37
5.1.1. G5 Stack Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê37
5.1.1.1. External Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê37
5.1.1.2. Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê37
5.1.2. G5 Cell Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê40
5.1.2.1. Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê40
5.1.2.2. Maximum Stack Deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê41
5.1.3. Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê41
5.2. Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê42
5.2.1. G5 Stack Switchgear Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê42
5.2.2. G5 Cell Interface Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê43
5.3. Using the Operator Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê44
5.3.1. The Dashboard Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê44
5.3.1.1. Warnings and Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê44
5.3.1.2. Stack Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê45
5.3.1.3. Stack Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê45
5.3.1.4. State-of-Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê45
5.3.1.5. Depth-of-Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê46
5.3.1.6. Cell Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê46
5.3.1.7. Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê47
5.3.1.8. Nuvation Energy BMS Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê48
5.3.2. The Details Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê51
5.3.2.1. Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê51
5.3.2.2. Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê51
5.3.2.3. Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê52
5.3.2.4. Cell Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê53
5.3.2.5. Thermistor Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê54
5.3.2.6. Open Wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê54
5.3.2.7. SoC Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê55
5.3.3. The Menu Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê57
5.3.3.1. Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê57
5.3.3.2. Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê57
5.3.3.3. Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê60
5.3.3.4. Locking and Unlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê60
5.3.3.5. About. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê61
5.3.4. The Status Banner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê62
5.3.4.1. Service Lockout Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê62
5.3.4.2. Self Check Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê62
5.3.4.3. Communication Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê62
5.3.4.4. Communication Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê63
5.3.4.5. G5 BMS Firmware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê73
6. Instructions for Stack Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê81

Appendix A: Battery Topology Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê82
Appendix B: Best Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê83
Excess Cable Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê83
Appendix C: Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê84
G5 Stack Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê84
G5 Cell Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê85
Appendix D: Mating Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê86
G5 Stack Switchgear Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê86
Power and Fan Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê86
I/O Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê86
Linkbus Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê88
Ethernet Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê88
Battery and DC Bus High Current Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê89
Earth Bonding Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê89
G5 Cell Interface Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê90
Cell Voltage and Temperature Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê90
Link In Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê91
Link Out Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ê92

The content in this document must be followed in order to ensure safe operation of Nuvation
Energy BMS.
The G5 High-Voltage BMS is to be installed in a location with restricted access.
Only skilled persons may install or service a system containing hazardous
voltages that may be present when the system is energized.
Do NOT energize the system until all connections to the Stack Switchgear unit
and Cell Interface modules have been made.

The wiring of the battery cell voltage and temperature sensing should be
verified before connecting to the Cell Interface modules. The temperature
sensing must be isolated from the cell voltage sensing. Although the Cell
Interface includes protective circuitry to make it more resilient to brief wiring
errors, the same circuitry can result in the battery cells being slowly
discharged. Over time, these wiring errors can cause damage to the Cell
Interface and/or the cells.
Properly insulate or remove any unused wires. Unused wires can couple
excessive system noise into Nuvation Energy BMS which can disrupt
communication and lead to undesirable behaviors.

Nuvation Energy BMS relies on your system charger to charge the battery
cells; do not leave your charger off while Nuvation Energy BMS is powered
from the stack for prolonged periods of time. Nuvation Energy BMS should be
shut down when the system is in storage to minimize the drain on the cells.
Insulated handling is required of any connector carrying potentials over 60 V
DC relative to chassis.
Please be aware of high voltages present in your system and follow all
necessary safety precautions.
The provided module enclosures are not fire enclosures.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 1Rev 1.0, 2023-05-19
G5 Faraday

1. Introduction
Thank you for choosing Nuvation Energy.
Nuvation Energy’s Stack Switchgear provides an integrated battery stack management solution that
includes all the hardware and software required to integrate a battery stack into your energy storage
system. Each Stack Switchgear unit contains Nuvation Energy High-Voltage BMS modules and is
designed to be used with other products in the Nuvation Energy BMS family.
1.1. About this Manual
This Nuvation Energy G5 High-Voltage BMS: NUVG5 Product Manual is a comprehensive manual,
providing:
▪Details about all the features offered by your Nuvation Energy G5 High-Voltage BMS
▪Mounting and wiring instructions to install this product safely
▪Guidance on integrating the device into your energy storage system
▪Guidance on operating the Nuvation Energy BMS Operator Interface
This document applies to Nuvation Energy BMS G5 Faraday software release
(Firmware version 5.7.0, Operator Interface version 0.64.0). Content may be
inaccurate or incomplete for other versions.
We thrive on your feedback and what we build is driven by your input.
Please submit support tickets to [email protected].
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 2Rev 1.0, 2023-05-19
G5 Faraday

2. Product Overview
The Nuvation Energy G5 High-Voltage BMS provides cell-level and stack-level control for battery
stacks up to 1500 VDC. The G5 Stack Switchgear and G5 Cell Interface modules operate together as
a complete system called the G5 High-Voltage BMS.
Both Nuvation Energy G5 Stack Switchgear and G5 Cell Interface are designed to enable UL 1973
certification of the battery stack. The UL 1973 Recognized Nuvation Energy BMS (Note: certification
pending) in each stack ensures safe battery operation and significantly reduces the effort of certifying
the energy storage system to meet UL 1973 and UL 9540.
Figure 1. G5 High-Voltage BMS.
A single Nuvation Energy G5 Stack Switchgear unit manages each stack and connects it to the DC
bus of the energy storage system. The G5 Stack Switchgear is a pre-configured assembly that
incorporates the major functions of Nuvation Energy G5 High-Voltage BMS into a rack-mountable unit
which includes stack monitoring, electrical disconnects, pre-charging, current sensing, fuses, and fan
control.
G5 Cell Interface modules in each stack connect directly to battery cells to measure cell voltages and
temperatures and provide cell balancing.
Typically, a single battery stack uses one G5 Stack Switchgear and one or more G5 Cell Interface
modules. A breakdown of a single battery stack is shown in Figure 2
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 3Rev 1.0, 2023-05-19
G5 Faraday

Figure 2. G5 High-Voltage BMS single system diagram
In a multi-stack G5 High-Voltage BMS configuration, as shown in Figure 3, each G5 Stack Switchgear
unit is responsible for monitoring the state and safety of one battery stack. All G5 Stack Switchgear
units connected to a single common DC bus in the system may be managed by a single Nuvation
Energy Multi-Stack Controller and operated via the Nuvation Energy Operator Interface. The Operator
Interface GUI provides a unified view and central control of multi-stack system.
Figure 3. G5 High-Voltage BMS multi-stack diagram
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 4Rev 1.0, 2023-05-19
G5 Faraday

2.1. G5 Stack Switchgear
The following variants of the Nuvation Energy G5 Stack Switchgear are available:
▪G5 Stack Switchgear, 1500 V, 100 A
▪G5 Stack Switchgear, 1500 V, 200 A
▪G5 Stack Switchgear, 1500 V, 300 A
The high-level system design of G5 Stack Switchgear is shown in Figure 2. Within a battery stack, the
G5 Stack Switchgear connects to the daisy-chained Nuvation Energy G5 Cell Interface modules. The
G5 Cell Interface modules convert cell voltage and temperature measurements to digital values to be
relayed to the G5 Stack Switchgear, and enable or disable cell balancing as required. Daisy-chaining
the G5 Cell Interface modules facilitates the design of flexible and scalable battery energy storage
systems.
The G5 Stack Switchgear has high-voltage, high-current connectors that are accessible on the front of
the unit. These connect the battery stack to the rest of the system, which is typically a common DC
bus. Safety precautions are required to handle and connect cables into this unit.
Figure 4. Nuvation Energy G5 Stack Switchgear
The external interfaces to this unit are:
▪Battery Stack and DC Bus connectors
▪Service Disconnect Switch
▪10/100 Base-T Ethernet RJ45 jack (Modbus-TCP)
▪Link Bus RJ45 connector
▪Fan control input and output
▪Power In
▪Power LED and Fault LED
▪Earth bonding connection (grounding stud)
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 5Rev 1.0, 2023-05-19
G5 Faraday

▪Enable, Shutdown, and Disconnect inputs
▪General purpose I/O
▪Factory Reset and Under Voltage Lockout (UVLO) Enable Config Switch
▪AC Fan Circuit Breaker
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 6Rev 1.0, 2023-05-19
G5 Faraday

2.2. G5 Cell Interface
The Nuvation Energy Cell Interface is the direct link between the individual battery stack cells and the
rest of the Battery Management System. It facilitates battery monitoring and balancing
functionalities.
In a stack managed by the G5 Stack Switchgear, one or more G5 Cell Interface modules are used to
convert and relay cell voltage and temperature measurements digitally to the G5 Stack Switchgear.
The NUVG5-CI-24, G5 Cell Interface - 24 channel can monitor up to 24 series-connected cells and up
to 8 external temperature sensors.
Figure 5. Nuvation Energy G5 Cell Interface
The external interfaces to this module are:
▪Cell Voltage and Temperature Sensors connector
▪2 Link Bus connectors
The G5 Cell Interface connects to the battery stack-referenced signals through high
voltage rated connectors. Safety precautions are required to handle and connect
cables into this module.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 7Rev 1.0, 2023-05-19
G5 Faraday

2.3. G5 BMS Software
The Nuvation Energy G5 BMS Software is composed of two parts: the Operator Interface and the G5
BMS Firmware.
2.3.1. Operator Interface
Figure 6. Operator Interface Dashboard
The Operator Interface is a browser-based graphical view of the system state, data, and
configuration.
Key Features:
▪Provides Unified View of Entire Battery - Access diagnostics and performance data of the
battery stack
▪Statistics - Provides stack-level voltage, temperature & current statistics for all cells
▪Real-Time - Streams measurements and control signals for real-time display and recording
▪Faults and Warnings - Aggregated for system-wide overview, plus detail drill-down for battery
pack diagnostics
▪SOC and SOH - Calculates State of Charge (SoC) and State of Health (SoH) for the battery stack
▪Communications Status - Ensures that measurements, control signals, and other data are
propagating properly throughout the entire system for safe operation
▪Flow-Through I/O - Provides a single entry point to all measurement and control points in the
BMS
2.3.2. G5 BMS Firmware
The G5 BMS Firmware is a highly configurable software that manages the stack operation and
controls. It enables the BMS to be used as a protection device against unsafe voltage, temperature,
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 8Rev 1.0, 2023-05-19
G5 Faraday

and current conditions in battery systems.
2.3.2.1. Key Features
▪Configuration Registers - Numerous configuration options, called 'registers', to tune the G5
High-Voltage BMS for the specific end-application.
▪Functional Safety - Functional safety according to IEC-60730-1 specification is accomplished
through several key capabilities of the software.
•Protection Functions - Provides protection functions for a battery against hazardous voltage,
temperature, and current conditions.
•Sensor Fault Detection - Detects sensor faults in cell voltage, temperature, stack voltage,
and stack current.
•Shorted Shunt Detection- Detects short circuit failures, and wiring defects.
•Microelectronic Fault Detection - Implements extensive internal verification to ensure that
processors, memories, and communication paths are functional and the safety software is
executing correctly.
•Contactor Life Tracking - Monitors the life of the contactors during the operation of the G5
Stack Switchgear. Contactor life is degraded when the contactors are opened at elevated load
currents.
•DC Bus and Stack Connector Temperature Monitoring - Monitors the temperature at the
high power connections to the G5 Stack Switchgear. High temperatures on these connectors
are an indication of untorqued connections which can lead to a battery fire.
▪Continuous Cell Balancing - A proprietary algorithm for continuous cell balancing leading to
shorter maintenance time. The battery does not have to remain above a specific cell voltage
threshold for balancing to occur.
▪Balancing Counters Per Cell - A counter per cell for the number of times a cell was passively
balanced is maintained and persisted on the G5 High-Voltage BMS. This data provides a clear
indication of cells which often have smaller relative capacities within the stack.
▪Configurable Modbus Points - Provides a configurable read/write access of G5 High-Voltage
BMS registers over the Modbus TCP interface.
▪Fault/Warning Bitfields - The status of all G5 High-Voltage BMS faults and warnings are
collected in separate bitfield registers. The fault/warning status can be determined by a few
register reads or mapped into Modbus points via the Configurable Modbus Points feature.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 9Rev 1.0, 2023-05-19
G5 Faraday

3. Functional Overview
The Nuvation Energy G5 High-Voltage BMS provides many functions to allow flexible and configurable
management/control of a stack. The following sections provides a brief summary of the product
functions.
Monitor DC Bus and Stack Voltages
The G5 Stack Switchgear measures both the DC Bus and the battery stack voltages. These
measurements allow for improved pre-charge and multi-stack capability.
Configurable for Different Battery Chemistries
The G5 Cell Interface is capable of measuring cells which vary in voltage between 1.6 and 4.3
volts. This range of voltage can support many lithium and lead-acid cell chemistries. A maximum
of 480 cells can be measured by using a maximum of 20 G5 Cell Interface modules connected to
one G5 Stack Switchgear.
Configurable Safe Limits of a Stack
As part of a UL 1973 certification, the safe operational range of a stack must be enforced by the
G5 Stack Switchgear. A factory configuration is used to provide the initial safety configuration and
is used within the certification process. Nuvation Energy provides a safety manual to guide the
process of how to configure a stack for certification review. Once a safety configuration is
established, the factory configuration can be locked to prevent further modification.
User Configurable Operational Range
After a stack is deployed, a user may choose to further limit the operational range of a stack. For
example the PCS may require a minimum voltage that is higher than the stack’s minimum voltage.
For cases such as this, the G5 Stack Switchgear has a user configurable set of operational limits
that can be set to meet these additional constraints. These configurations can be persisted into
non-volatile storage and write protected with a password. A short list of these operational limits
include:
▪High and Low Cell Voltage
▪High and Low Stack Voltage
▪High Charge Current and High Discharge Current
▪High and Low Cell Temperature
GPI/GPO Interfaces
Two GPIs and two GPOs are available to allow interfacing with external connections such as:
▪PCS emergency OFF
▪E-Stop output
▪External indicator LEDs
▪Ground Fault Detector Input
▪Manual clear faults
▪DC-OK
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 10 Rev 1.0, 2023-05-19
G5 Faraday

Internal Temperature Monitoring
The G5 Stack Switchgear has seven internal thermal measurements which are connected to a
warning/fault. Likewise, each G5 Cell Interface module monitors its internal temperature and
reduces passive balancing at high temperatures.
Dedicated Enable, Shutdown, and Disconnect inputs
The G5 Stack Switchgear provides separate Enable, Shutdown, and Disconnected inputs. These
inputs allow for external control to power on the Battery Management System, gracefully
shutdown the Battery Management System, or safely open the contactors to disconnect the
battery stack.
External Fan Control
The G5 Stack Switchgear can be used to control external AC or DC fans for cooling the battery
cells. The fans are enabled by the Battery Management System when battery cell temperatures
exceed configurable thresholds. There is also a manual control configuration to allow external
control of the fans via software command.
Cell Open Wire Detection and Diagnostics
The G5 Stack Switchgear is capable of detecting wiring and circuit problems on each cell voltage
channel. The following scenarios are detectable:
▪Open circuits
▪Short circuits
▪High impedance connections/wiring
▪Internal Battery Management System hardware failures
Under Voltage Lockout
When a battery monitoring device derives its power from the battery stack, it is vital that during
critically low cell/stack voltages that all derived power is removed. The G5 Stack Switchgear
provides an Under Voltage Lockout (UVLO) fault that can be used to disconnect the power of its
monitoring electronics to prevent further damage to critically low cells. If the UVLO event were to
occur, the G5 Stack Switchgear can be restarted with the use of 24V dry-contact switch.
Sunspec Modbus TCP with Configurable Points
The G5 Stack Switchgear provides MESA 801/802/803 data models over its Modbus TCP port.
Furthermore, the device can be configured to map internal data registers to a reserved set of
Modbus points. This functionality allows internal data that is not within Sunspec data models to be
accessed over Modbus TCP.
Continuous Balancing
The G5 Stack Switchgear implements a balancing algorithm that estimates charge imbalances of
the stack cells and applies balancing to these imbalanced cells during operation. The use of
continuous balancing significantly increases operational time of the battery system managed by
the Nuvation Energy BMS by decreasing the maintenance time to balance cells within the stack.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 11 Rev 1.0, 2023-05-19
G5 Faraday

4. Installation Instructions
4.1. Safety Instructions
The content in this document must be followed in order to ensure safe operation of Nuvation
Energy BMS.
The G5 High-Voltage BMS is to be installed in a location with restricted access.
Only skilled persons may install or service a system containing hazardous
voltages that may be present when the system is energized.
Do NOT energize the system until all connections to the Stack Switchgear unit
and Cell Interface modules have been made.

The wiring of the battery cell voltage and temperature sensing should be
verified before connecting to the Cell Interface modules. The temperature
sensing must be isolated from the cell voltage sensing. Although the Cell
Interface includes protective circuitry to make it more resilient to brief wiring
errors, the same circuitry can result in the battery cells being slowly
discharged. Over time, these wiring errors can cause damage to the Cell
Interface and/or the cells.
Properly insulate or remove any unused wires. Unused wires can couple
excessive system noise into Nuvation Energy BMS which can disrupt
communication and lead to undesirable behaviors.

Nuvation Energy BMS relies on your system charger to charge the battery
cells; do not leave your charger off while Nuvation Energy BMS is powered
from the stack for prolonged periods of time. Nuvation Energy BMS should be
shut down when the system is in storage to minimize the drain on the cells.
Insulated handling is required of any connector carrying potentials over 60 V
DC relative to chassis.
Please be aware of high voltages present in your system and follow all
necessary safety precautions.
The provided module enclosures are not fire enclosures.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 12 Rev 1.0, 2023-05-19
G5 Faraday

4.2. G5 Cell Interface
4.2.1. Installation Overview
During all stages of the installation, appropriate Personal Protective Equipment (PPE)
must be worn. This is especially critical when working with live voltages.
To complete the installation of the G5 Cell Interface, the following is required:
Cables
To connect your G5 Cell Interface you will require the following cables for each module:
▪1x Voltage and Thermistor cable
▪1x Ethernet cable
These cables are available for purchase as a kit.
The instructions below are for applications using cable harnesses purchased from Nuvation Energy. To
build custom cables, refer to G5 Cell Interface Connectors for connector pin-out and specifications.
Tools and Materials
You will need the following tools and materials to complete your G5 Cell Interface installation:
▪Fasteners and tools for attaching the G5 Cell Interface to the end desired surface.
▪G5 Cell Tap Checker - To test cable connectivity. Contact [email protected] to
purchase
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 13 Rev 1.0, 2023-05-19
G5 Faraday

4.2.2. Mechanical Installation
4.2.2.1. Dimensions and Weight
The overall dimensions of the G5 Cell Interface are 118.6mm x 116.3mm x 25.4mm and weighs
approximately 116g. The G5 Cell Interface is available in a bulkhead-mountable enclosure as shown
below.
Figure 7. Mechanical Drawing of G5 Cell Interface
Please refer to https://www.nuvationenergy.com/technical-resources for access to
CAD files.
4.2.2.2. Installation Location and Position
Mounting Clearances
The G5 Cell Interface produces up to 15 W during cell balancing. A portion of this heat is transferred
to the bulkhead.
Extra space should be provided around the G5 Cell Interface module to allow for improved airflow and
ease of installation/maintenance.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 14 Rev 1.0, 2023-05-19
G5 Faraday

4.2.2.3. Mounting Instructions
The G5 Cell Interface is rated to operate in the temperature range of -20 °C to 60 °C. It is designed
for indoor use.
The G5 Cell Interface should be mounted against a flat surface with vent above the Nuvation Energy
logo pointing up to the sky.
Ensure the enclosure is connected securely to Earth, either by grounding the
mounting surface or by using a dedicated Earth Bonding Conductor.
Ensure appropriate fasteners (not included) are used to mount the G5 Cell Interface. These fasteners
will vary depending on the material and construction of the mounting surface.
It is suggested to use #8-32 screws with a split lock washer for the mounting holes provided on each
side flange of the G5 Cell Interface.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 15 Rev 1.0, 2023-05-19
G5 Faraday

4.2.3. Electrical Connections
The G5 Cell Interface connects to the battery stack-referenced signals through high-
voltage rated connectors. Safety precautions are required to handle and connect
cables into this module.
4.2.3.1. Getting Started
Connection sequence
▪Step 1: Connect the Cell Voltage and Temperature Cable
▪Step 2: Connect the Link Bus Cable

The wiring of the battery cell voltage and temperature sensing should be verified
before connecting to the Cell Interface modules. The temperature sensing must be
isolated from the cell voltage sensing. Although the Cell Interface includes protective
circuitry to make it more resilient to brief wiring errors, the same circuitry can result
in the battery cells being slowly discharged. Over time, these wiring errors can cause
damage to the Cell Interface and/or the cells.
4.2.3.2. Connect the Cell Voltage and Temperature Cable

Your G5 Stack Switchgear is pre-configured to expect a defined number of
thermistors based on the information provided to Nuvation Energy during order
fulfillment. Failure to use the same number of thermistors will result in undesirable
G5 Stack Switchgear behavior. Please contact [email protected] if there
is a change requiring a G5 Stack Switchgear configuration update.
The Temperature cable provides 10 kΩ NTC thermistors for temperature measurement of the cells
and/or surrounding area. These sensors are used by Nuvation Energy BMS to detect over and under
temperature conditions and adjust battery current limits to compensate for cell temperature.
Cable Isolation
Because the sensors are referenced to the CELL0 input on the G5 Cell Interface, care must be taken
to ensure that they are electrically isolated from any common or ground potential, and from all
other cell voltage terminals of all G5 Cell Interface modules in the system
The thermistors must also be isolated from the cell voltage terminals, as well as any metal work or
other exposed conductors, in such a way that they will not make an electrical connection to a cell
terminal in the event of vibration/failures.
Connection Procedure
If you are building your own cables, please refer to the pin out for this connector in
Cell Voltage and Temperature Connector.
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Document ID: NE-DS-011 16 Rev 1.0, 2023-05-19
G5 Faraday