VE.Bus BMS

The VE.Bus BMS is a battery management system designed to specifically protect individual cells of Victron Energy lithium-iron-phosphate (LiFePO4 or LFP) batteries against overvoltage, undervoltage, and overheating. It manages the disconnection of loads and chargers to ensure battery safety and longevity.

This VE.Bus BMS is compatible exclusively with Victron Energy lithium-iron-phosphate (LiFePO4 or LFP) batteries that include cell balancing, temperature and voltage monitoring (BTV).

The VE.Bus BMS is designed to protect 12 V, 24 V and 48 V battery systems. Its operating voltage range is 9 to 70 V DC.

It connects to Victron Energy LiFePO4 batteries via two sets of M8 circular connectors. These connectors link the BMS to the BTVs (balancing, temperature and voltage monitoring) integrated in each battery.

You can install up to five batteries in parallel and up to four batteries in series. This allows you to build a 48 V battery bank up to 1500 Ah.

The VE.Bus BMS communicates with all Victron Energy VE.Bus products, including MultiPlus inverters/chargers, Quattro models, and Phoenix inverters. The connection is made via a standard RJ45 UTP cable.

In case of imminent undervoltage on the cells, the BMS stops or disconnects connected loads. A pre-alarm output is also activated at least 30 seconds before load disconnection to warn the user.

In case of imminent overvoltage or overheating on the cells, the BMS reduces the charge current (for VE.Bus products) and stops or disconnects the battery chargers.

The load disconnect output is normally high and goes floating in case of imminent undervoltage risk on the cells. It can be used to remotely control the on/off of a load or an electronic load switch (such as a BatteryProtect). The maximum current of this output is 2 A.

The charge controller's disconnect output is normally high and becomes floating in case of imminent overvoltage or overheating on the cells. It can be used to remotely control the on/off state of a charger, a Cyrix-Li-Charge relay, or a Cyrix-Li-ct battery coupler. The maximum current of this output is 10 mA.

The pre-alarm output is normally floating and goes high when cell voltage drops to a critical level (default 3.1 V/cell). It activates at least 30 seconds before the load disconnects to provide a warning. Maximum current on this output is 1 A (not short-circuit protected).

The VE.Bus BMS operating voltage range is 9 to 70 V DC.

Enabled (blue): Indicates that VE.Bus products are enabled.Cell > 4 V or temperature (red): Indicates that the charger disconnect output is low due to an imminent overvoltage or overheating on the cells.Cell > 2.8 V (blue): Indicates that the charge disconnect output is high.

The VE.Bus BMS has a matte black ABS housing. Its dimensions are 105 x 78 x 32 mm (H x W x D) and its weight is 0.1 kg.

The VE.Bus BMS enclosure has an IP20 protection rating.

Yes, the UTP cable connecting the BMS to the inverter or charger/inverter also carries the negative battery connection to the BMS. For this reason, do not wire the BMS battery negative connector to avoid ground loops.

The BTV terminals of multiple batteries can be connected in series (daisy-chained) using the two M8 circular conductor assemblies. Once all batteries are interconnected, the two remaining cables are then connected directly to the VE.Bus BMS.

The VE.Bus BMS is specifically designed to protect Victron Energy lithium-iron-phosphate (LiFePO4 or LFP) batteries. To do this, it connects to Victron LiFePO4 batteries equipped with a BTV system (balancing, temperature and voltage monitoring) via M8 circular connectors.

This BMS is compatible with 12 V, 24 V, and 48 V systems. It allows up to five batteries to be connected in parallel and up to four batteries in series, enabling a 48 V battery bank with a capacity of up to 1500 Ah.

It communicates with Victron Energy MultiPlus converters, Quattro units, and Phoenix inverters via a standard RJ45 UTP cable. Its operating voltage range is 9 to 70 V DC.

The VE.Bus BMS protects each individual cell of Victron lithium-iron-phosphate (LiFePO4) batteries against overvoltage, undervoltage, and overheating.

Its protection functions include:

Stopping or disconnecting loads in case of imminent undervoltage on the cells. Reducing the charging current in case of imminent overvoltage or overheating on the cells (specifically for VE.Bus products). Stopping or disconnecting battery chargers in case of imminent overvoltage or overheating on the cells. For non-VE.Bus products, it has dedicated outputs: a load disconnection output (max. 2 A), a charger disconnection output (max. 10 mA), and a pre-alarm output (max. 1 A) that activates 30 seconds before load disconnection in case of imminent undervoltage.

Blue and red LED indicators signal operating status and alerts (e.g., cell > 4 V or high temperature, or cell > 2.8 V).

Installing the VE.Bus BMS requires several key connections to ensure proper operation and protection of your batteries:

Battery connections: Victron lithium-iron-phosphate (LiFePO4) batteries connect to the VE.Bus BMS via two sets of M8 circular conductors. If you have multiple batteries, their BTVs (balancing, temperature and voltage monitoring) must be connected in series (daisy-chaining).

VE.Bus product connections: The BMS connects to MultiPlus, Quattro or Phoenix inverters using a standard UTP RJ45 cable. This UTP cable also provides the negative battery connection to the BMS. In this case, to avoid ground loops, it is critical not to wire the BMS negative connector.

Positive power feed: The VE.Bus BMS positive power cable must be connected to the system positive.

AC Detector: An AC Detector is included with the VE.Bus BMS and must be installed in the MultiPlus or Quattro (not required for MultiPlus-II models) to restart the device when AC power is available after a shutdown due to low cell voltage. In systems with multiple units configured in parallel or three-phase, the AC Detector must be wired only to the master or leader unit.

Control panels: A Digital Multi Control panel must be connected to the VE.Bus BMS and not directly to a MultiPlus or Quattro. A ColorControl panel, however, must be connected directly to the MultiPlus or Quattro.

It is also essential to ensure that the Li-ion assistant or ESS assistant software is loaded in all MultiPlus/Quattro/inverter units for correct operation.