Victron Energy VE.Bus BMS NG Product Manual

1. Safety Precautions

Installation must strictly follow national safety regulations, including enclosure, installation, creepage, clearance, casualty, markings, and segregation requirements of the end-use application.

Installation must be performed by qualified and trained installers only.

Carefully study the product manuals of all connected devices before installing them.

Switch off the system and check for hazardous voltages before altering any connection.

• Do not open the lithium battery.
• Do not discharge a new lithium battery before it has been fully charged first.
• Charge a lithium battery only within the specified limits.
• Install the battery in a vented area.
• Do not mount the lithium battery upside down.
• Do not install batteries in a living area.
• Check if the lithium battery has been damaged during transport.

2. General Description

The VE.Bus BMS NG is a Battery Management System (BMS) designed specifically for Victron Energy Lithium NG batteries (LiFePO4). These batteries are available in 12.8 V, 25.6 V, and 51.2 V, and in various capacities.

The VE.Bus BMS NG interfaces with and protects Victron Lithium NG batteries in systems that include a Victron VE.Bus inverter/charger or VE.Bus inverter. It performs key functions such as enabling/disabling charge and discharge based on battery conditions.

Batteries can be connected in series, parallel, or a combination to build battery banks suitable for 12 V, 24 V, or 48 V system voltages.

• For 12 V and 24 V configurations, up to 50 batteries can be used.
• For 48 V configurations, the maximum is 25 batteries.

This results in a maximum storage capacity of:

• 192 kWh for 12 V systems
• 384 kWh for 24 V systems
• 128 kWh for 48 V systems

For complete specifications, refer to the Victron Lithium NG battery product page.

Cell-level protection

The BMS monitors and protects each individual cell of the connected battery or battery bank. Based on the status signals received from the battery, it will:

• Trigger a pre-alarm to warn of an imminent cell undervoltage.
• Disconnect or shut down loads if a cell undervoltage condition occurs.
• Turn off the inverter in VE.Bus inverter/chargers or VE.Bus inverters in case of cell undervoltage.
• Reduce charge current if a cell overvoltage or overtemperature is detected in VE.Bus inverter/chargers or VE.Bus inverters.
• Disconnect or shut down chargers in case of cell overvoltage or overtemperature.

2.1. Features and Functionality

• Bluetooth Smart: Enables wireless configuration, monitoring, and firmware updates via smartphones and tablets using the VictronConnect App. Includes Instant Readout for key BMS and battery data.
• Load Disconnect output: Controls the remote on/off input of loads with remote on/off functionality. Output is normally high, becomes free-floating when cell undervoltage is imminent. Max output current: 1A.
• Charge disconnect output: Controls the remote on/off port of chargers. Output is normally high, becomes free-floating in case of imminent cell overvoltage or overtemperature. Max output current: 500mA.
• Remote on/off terminal: Allows remote control of Load and Charge Disconnect outputs. Consists of two terminals: Remote L and Remote H. Requires a switch or relay contact between L and H, or H switched to battery plus or L switched to battery minus. An on/off switch or default wire loop is required for correct operation.
• Pre-alarm output: Triggers a visible or audible warning when battery voltage is low, activating before the Load Disconnect output is disabled. Can drive a relay, LED, or buzzer. Max output current: 1A. Output is normally free-floating, becomes high in case of imminent cell undervoltage.
• Configurable discharge floor: Defines the minimum SoC to prevent excessive discharge and ensure enough energy remains for self-discharge after a low SoC shutdown. A low SoC warning level can be set, triggering a warning in VictronConnect. The pre-alarm output is activated when the warning level is reached. A low SoC alarm is triggered when the discharge floor is reached, and the BMS deactivates the ATD output.
• LED indicators: Blue Bluetooth Status LED, Red Error LED, VE.Bus Status LED.
• Connectivity and communication with GX device: Enables on/off/charger-only control of VE.Bus products via a GX device.
• GX DVCC control of solar chargers: Simplifies solar charger control compared to VE.Bus BMS V1.
• Separate power input and output connections for GX devices: The GX-Pow output supplies power to the GX device from either the battery or the Aux-In input, whichever voltage is higher.
• True remote on/off terminal: Keeps the inverter in low power mode even when AC input is available.
• Optional auxiliary power for remote access: An AC-DC adapter can be connected to the Aux-In input to maintain GX device operation and remote access via VRM even when the system is otherwise shut down.

2.2. What's in the box?

• 1x VE.Bus BMS NG
• 1x Mains detector
• 1x 0.3m RJ45 UTP cable
• Piece of Velcro adhesive hook and loop tape

Note: The DC power cable to power the BMS is not included. Use any 1-wire cable with at least 0.75mm² (AWG 16) and a 1A inline fuse.

3. Installation

3.1. System Examples

3.1.1. Basic system

A basic system includes a MultiPlus-II Inverter/charger, a VE.Bus BMS NG, and a Lithium NG Battery or battery bank.

3.1.2. System with a GX device, on/off switch and pre-alarm circuit

This system includes an AC source, circuit breaker, MultiPlus-II Inverter/charger, remote on/off switch, VE.Bus BMS NG, Cerbo GX, an optional AC-DC power supply for the GX device, a pre-alarm warning circuit, and a Lithium NG Battery or battery bank.

3.1.3. System with a BatteryProtect and solar charger

This system includes an AC source, circuit breaker, MultiPlus-II Inverter/charger, solar charger, VE.Direct non-inverting remote on/off cable, VE.Bus BMS NG, BatteryProtect, and DC loads, connected to a Lithium NG Battery or battery bank.

3.1.4. Three-phase system with a Digital Multi Control

This system includes a Digital Multi Control, MultiPlus-II Inverter/chargers configured for three-phase operation, a VE.Bus BMS NG, and a Lithium NG Battery or battery bank.

3.1.5. System with an alternator

This system includes an AC source, circuit breaker, Orion DC-DC charger, VE.Bus BMS NG, MultiPlus-II Inverter/charger, starter monitor and alternator, a 12V starter battery, and a Lithium NG Battery or battery bank.

3.2. Basic Installation

1. Connect the battery BMS cables to the BMS. Refer to the Lithium NG Battery manual for installation instructions.
2. Connect the inverter/charger or inverter positive and negative cables to the battery. Ensure the firmware is updated to the most recent version.
3. Connect the battery positive via the red power cable with the fuse to the BMS "Battery+" terminal.
4. Connect the VE.Bus port of the Inverter/charger or inverter to the "MultiPlus/Quattro" port of the BMS using the included RJ45 cable.
5. For new style MultiPlus and Quattro models, the mains detector is not required and can be disposed of.

Note: The BMS does not have a battery negative connection; it obtains it from the VE.Bus. Therefore, it cannot be used without a VE.Bus Inverter/charger or VE.Bus inverter.

3.2.1. Minimal VE.Bus firmware

Incompatibility Warning: Inverter/chargers or inverters with small processors labeled 19XXXXX or 20XXXXX are not supported. Use the VE.Bus BMS with Lithium Smart batteries instead.

Important: Firmware requirements before connecting the BMS:

1. Update VE.Bus firmware to version xxxx489 or higher.
2. If firmware is between xxxx415 and xxxx489, install either the VE.Bus BMS or ESS assistant on the inverter/charger.
3. Devices with firmware versions below xxxx415 will trigger a VE.Bus Error 15. If firmware cannot be updated to version xxxx415 or higher, the VE.Bus BMS NG cannot be used.

3.2.2. Battery BMS cable connections

For multiple batteries in parallel and/or series, connect the BMS cables in series (daisy-chained). Connect the first and last BMS cable to the BMS. Extension cables are available if needed.

3.2.3. Mains detector

The mains detector is not required for new style MultiPlus and MultiPlus-II, Quattro-II, and inverter models. Its purpose is to restart the inverter/charger when AC supply becomes available after a BMS-initiated shutdown due to low cell voltage.

In multi-unit systems, wire the mains detector in the master or leader unit only. Use one AC wire pair for MultiPlus and both for Quattro.

3.3. Controlling DC loads and chargers

3.3.1. DC load control

DC loads with remote on/off terminals can be controlled by the BMS Load disconnect output. Loads that do not have remote on/off terminals can be disconnected using a BatteryProtect.

Note: Be aware of residual current in the off state, as it can damage the battery over time.

3.3.2. DC charge control

3.3.3. Controlling inverter/chargers, solar chargers and other battery chargers

Chargers are controlled via DVCC (if a GX device is present) or via their remote on/off terminals using the BMS Charge disconnect output. For systems without a GX device, use the Charge disconnect output to control chargers via remote on/off, a BatteryProtect, or a Cyrix-Li-Charge.

3.3.4. DVCC operation with VE.Bus BMS NG

DVCC allows a GX device to control compatible devices like solar chargers and Inverter RS/Multi RS. DVCC must be enabled for the GX device to control these chargers by setting their maximum charge current limit to zero when the BMS requests charging to stop.

The BMS does not control the charge voltage of solar chargers or inverters. In an ESS system, the Multi controls the charging voltage. In non-ESS systems, all devices must be set to the appropriate lithium charge algorithm.

AC chargers and smaller Phoenix inverters require separate signal wiring to control them.

3.3.5. Charger control via Charge disconnect

For chargers not DVCC compatible or in systems without a GX device, use the Charge disconnect output. Connect it to the H terminal of the charger's remote on/off connector. The output becomes free-floating at high cell voltage or low temperature, stopping the charge.

An Inverting remote on-off cable can be used for chargers that activate when the terminal is pulled low. Alternatively, a Cyrix-Li-Charge relay can be used.

3.3.6. Charging with an alternator

Alternator charging can be controlled using a DC-DC charger (e.g., Orion-Tr Smart) or a SolidSwitch 104. These devices are controlled by the BMS Charge disconnect output wired to their remote on/off H terminal.

3.4. Remote on/off terminal

The BMS remote on/off terminal can turn the entire system on and off. It keeps the inverter in low power mode even when connected to AC In. The system turns on when the L and H terminals are interconnected, or when L is pulled to battery minus, or when H is high.

A typical application is switching off the system based on a state of charge (SoC) from a BMV. The wire loop between L and H must be plugged in for the BMS to switch on.

3.5. GX device

For GX device control of solar chargers, Inverter RS, Multi RS or Multis, the GX device Venus OS firmware must be version 2.80 or above.

Installation:

1. Connect the GX device VE.Bus port to the BMS Remote panel port via an RJ45 cable.
2. Connect the GX device "power +" terminal to the BMS GX-Pow terminal and the "power -" terminal to the negative battery terminal.
3. Connect the positive wire of an optional AC-DC power supply to the BMS Aux-in terminal and the negative wire to the negative battery terminal.
4. Perform a VE.Bus re-detect system action on the GX device.

GX-Pow and Aux-In terminals functionality: The GX-Pow output supplies power to the GX device. The Aux-In input ensures continued GX device operation and remote access via VRM, even if the system is otherwise shut down.

3.6. Connecting a Digital Multi Control or a VE.Bus Smart dongle

If using a VE.Bus Smart dongle or Digital Multi Control (DMC), connect it to the BMS Remote panel port. Both offer on/off/charger-only control of the inverter/charger. The Phoenix Inverter Control panel can also be connected.

In systems with a DMC, GX device, or VE.Bus Smart dongle, on/off/charger-only control is only possible via the DMC. The GX device or VE.Bus Smart dongle can also be connected to the MultiPlus/Quattro port for easier wiring.

Note: The VE.Bus Smart dongle measures battery voltage and must have its Battery+ terminal connected to the positive battery terminal. It draws a small current (up to 9mA) even when the BMS signals a low cell warning.

4. Configuration and Settings

4.1. Configuration of chargers and loads

Ensure chargers and loads are correctly configured, particularly their maximum combined charge and discharge currents, to avoid exceeding battery limits.

Maximum charge current: The maximum continuous charge current is 1C. A charge current of 0.3C is recommended for optimal performance.

Maximum discharge current: The maximum continuous discharge current is 1C. The maximum pulse discharge current is 2C for a maximum of 10 seconds. A discharge current of 0.5C is recommended for optimal performance.

Warning: Chargers and loads not controlled by the BMS can permanently damage the battery.

4.2. Power up for the first time

The VE.Bus BMS NG switches on when the following conditions are met:

1. Battery connection: The Bat+ of the 6-pin terminal block must be connected to Battery Plus.
2. VE.Bus inverter/charger connection: The RJ45 labelled MultiPlus/Quattro port must be connected to a VE.Bus inverter/charger or VE.Bus inverter. The BMS derives its battery negative through the VE.Bus link.

The VE.Bus BMS assistant configuration is done automatically once the connection between the VE.Bus device and the BMS is established.

4.3. VE.Bus BMS NG and Lithium NG battery settings

Use the VictronConnect app to configure the BMS settings after powering up. Battery capacity, voltage, and number of batteries are automatically detected and cannot be edited, but should be verified.

Battery monitor settings:

• Charged voltage: Voltage above which SoC resets to 100%, if tail current and charged detection time conditions are met.
• Tail current: Current below which SoC resets to 100%. Default: 4% (adjustable).
• Charged detection time: Time charged voltage and tail current must be maintained to trigger synchronization. Default: 3 minutes (adjustable).
• Low SoC warning level: Level at which a warning is issued before the discharge floor is reached. Default: 12% (adjustable). The pre-alarm output is activated when this level is reached.
• Discharge floor: Default: 10% (adjustable). Sets the minimum SoC to prevent excessive discharge and ensure energy for self-discharge. Reaching the discharge floor triggers a low SoC alarm and disables ATD. Setting to zero is not recommended.
• State of charge: Allows manual setting of the current SoC.
• Synchronize SoC to 100%: Manually synchronize SoC to 100%.

4.4. Update BMS and Battery firmware

Firmware updates are carried out via the VictronConnect app.

General notes on firmware updates:

• Only update if necessary.
• Avoid unnecessary updates.
• Read the changelog first (available on Victron Professional).
• Use this feature with care; avoid updating a running system unless problems occur or before the first startup.

Notes on updating the VE.Bus BMS NG and Lithium NG battery firmware:

• The firmware update does not cause a full system shutdown.
• During the update, the Charge disconnect output opens, preventing battery charging.
• If the update fails, the Load disconnect output opens after 120 seconds as a safety measure.

Updating the firmware:

1. Refer to the firmware update chapter in the VictronConnect manual for detailed instructions.
2. VictronConnect will notify you automatically if a newer firmware version is available once a connection with the VE.Bus BMS NG is established.

Which firmware version do I have? The firmware version is visible on the VictronConnect Product info page of the BMS.

5. Monitoring and Control

5.1. Important Warning

Lithium batteries are expensive and can be damaged due to over-discharge or overcharge. The BMS shutdown due to low cell voltage should be a last resort. It is recommended to switch off the system automatically after a defined state of charge using the BMS discharge floor limit, or use the BMS remote on/off port as a system on/off switch.

Damage due to over-discharge can occur if small loads slowly discharge the battery when the system is not in use. In case of doubt about residual current draw, isolate the battery by opening the battery switch, pulling the battery fuse(s), or disconnecting the battery plus when the system is not in use.

A residual discharge current is especially dangerous if the system has been discharged completely and a low cell voltage shutdown has occurred. A residual current of just 10mA can damage a 200Ah battery if the system is left discharged for more than 8 days.

If a low cell voltage disconnect has occurred, immediate action (recharge the battery) is required.

5.2. Monitoring and control via VictronConnect

The VictronConnect app allows monitoring and control of the battery and BMS. It has three pages: status, battery, and history.

Status page: Provides information about the current battery and BMS status, including State of Charge, Mode, Allowed to charge/discharge, Voltage, Current, Power, Consumed Ah, and Time remaining.

Battery page: Provides information about the installed battery bank and individual batteries, including Balancer status, Min/Max cell voltage and temperature, number of batteries, and individual battery details like serial number, capacity, firmware version, and cell voltages.

History page: Shows historical data such as Deepest discharge, Cumulative AH drawn, Discharged/Charged energy, Synchronisations, Cycles, Last full charge, Min/Max battery voltage and temperature.

5.3. LEDs, warnings, alarms and error codes

The BMS is equipped with three LEDs: Bluetooth Status LED, Error LED, and VE.Bus Status LED, indicating the operating state and faults.

Warning, alarm, and error codes are reported via the VictronConnect app.

• A warning indicates a problem that, if not corrected, will result in a system shutdown.
• An alarm indicates the reason for the system shutdown.

LEDs:

• Bluetooth Status LED: Off (no power/Bluetooth disabled), Blue on (Bluetooth device connected), Blue blinking (Bluetooth active, no device connected).
• Error LED: Off (no warning/alarm/error), Red blinking (warning active), Red on (alarm/error active).
• VE.Bus Status LED: Off (system off, low-power mode), Single blink every 10 seconds (system on, sending info frames), LED flashes rapidly (BMS stuck in bootloader mode).

Warning codes:

• W-B01: Low cell voltage - Charge battery or reduce load.
• W-B05: Communication with battery lost - Check cables between BMS and Battery.
• W-B07: Low SoC - Charge battery or reduce load.

Alarm codes:

• A-B01: Low cell voltage - Charge battery; loads will be turned back on when sufficiently charged.
• A-B05: Communication with battery lost - Check cables between BMS and Battery.
• A-B07: Low SoC - Charge battery; loads will be turned back on when sufficiently charged.
• A-B08: Low bank voltage - Charge battery; loads will be turned back on when sufficiently charged.
• A-B09: High battery temperature - Reduce ambient temperature.

Error codes:

• E-B01: Battery configuration invalid - Check 'Battery' tab in VictronConnect and cable connections.
• E-B05: Battery configuration invalid - Check 'Battery' tab in VictronConnect and cable connections.
• E-B09: Battery voltage not allowed - Check battery voltage and settings in VictronConnect app.
• E-B11: Hardware error - Contact your Victron dealer.

6. Frequently Asked Questions

• Q1: Inverter/charger not switching on after disconnecting VE.Bus BMS NG? The inverter/charger enters emergency mode, charging at a maximum of 5A. It will not invert if AC input is disconnected, as it cannot verify battery health.
• Q2: Batteries empty, inverter/charger not charging? Connect a small battery charger (e.g., 5A) until battery voltage reaches 12, 24, or 48V.
• Q3: BMS signals low cell voltage? The inverter/charger enters "charger only mode". Batteries are charged when AC input is available; otherwise, the inverter/charger is off.
• Q4: BMS signals high cell voltage? The inverter/charger switches to bulk charging with reduced current to allow cell balancing.
• Q5: BMS displays VE.Bus Error 15? This indicates incompatible VE.Bus products or firmware versions. Update the inverter/charger firmware to version xxxx415 or higher.

7. Technical Specifications VE.Bus BMS NG

Electrical

General

Enclosure

Standards

Min. power rating (External AC-DC adapter if installed): 1 A @ 12 V - If the nominal output voltage is > battery voltage, the AC-DC adapter takes over the power supply of the GX device.

8. Appendix

8.1. Appendix A

1. Loads controlled by Load disconnect output:

• Inverters: VE.Direct and Smart Inverters (connect to terminal H of the 2-pole connector).
• DC-DC converters: TR-type converters, Orion 12/24-20, Orion XS (connect to the right-hand terminal of the 2-pole connector).
• Battery Protect and Smart Battery Protect: Connect to terminal 2.1 (right hand terminal) for BatteryProtect, and H pin of the 2-pole connector for Smart Battery Protect.
• Cyrix-Li-Load: Connect to the control input.

2. Loads requiring an inverting remote on-off cable (article number ASS030550100 or -120):

• VE.Bus inverters and VE.Bus Inverter Compact rated at 1200VA or more.

3. Solar charge controllers controlled by Charge disconnect output:

• BlueSolar MPPT 150/70 and 150/80 CAN-bus (connect to the left hand terminal of the 2-pole connector (B+)).
• SmartSolar MPPT 150/45 and higher, 250/60 and higher (connect to the right-hand terminal (+) or left-hand terminal (H) of the 2-pole connector).

4. Solar charge controllers requiring a VE.Direct non-inverting remote on-off cable (article number ASS030550320):

• BlueSolar MPPT models (except 150/70 and 150/80 CAN-bus).
• SmartSolar MPPT up to 150/35.

5. Battery Chargers:

• Smart IP43 Chargers (connect to terminal H of the 2-pole connector).
• Skylla TG battery chargers (use non-inverting remote on-off cable, article number ASS030550200).
• Skylla-i battery chargers (use Skylla-i remote on-off cable, article number ASS030550400).
• Other battery chargers (use a Cyrix-Li-Charge).

8.2. Displaying VE.Bus BMS NG SoC on a GX Device

The VE.Bus BMS NG transmits State of Charge (SoC) over the VE.Bus network. This guide explains how to enable and display the SoC on a GX device.

Enabling "Battery Monitor" on the MultiPlus/Quattro:

To forward SoC to the GX device, enable the Battery Monitor setting on the MultiPlus/Quattro via Remote VEConfigure or VictronConnect.

Using Remote VEConfigure:

1. Download the Remote VEConfigure file from the device.
2. Open the file in VEConfigure.
3. In the General tab, tick "Battery monitor". (Note: "Battery capacity" and "Charge efficiency" are managed by the VE.Bus BMS NG).
4. Click File → Exit and confirm saving the changes.
5. Click 'Yes'.
6. Upload the updated file back to the MultiPlus/Quattro using Remote VEConfigure.

Using VictronConnect:

1. Connect a MK3-USB interface between the MultiPlus/Quattro and the device running VictronConnect (PC or Android).
2. Open VictronConnect.
3. Select the MultiPlus/Quattro from My devices.
4. Navigate to Settings → General.
5. Enable the "Battery monitor" option.

Selecting the battery monitor in the GX device:

This step is only required if multiple battery monitoring devices are connected to the GX device. Ensure that the MultiPlus/Quattro is selected as the active battery monitor by navigating to Settings → System Setup → Battery monitor and enabling the option on the MultiPlus/Quattro.

8.3. Enclosure dimensions VE.Bus BMS NG

The enclosure dimensions of the VE.Bus BMS NG are provided in millimeters.