victron energy VE.Bus BMS Battery Management System User Manual
- June 16, 2024
- victron energy
Table of Contents
VE.Bus BMS
General Description
Protects each individual cell of a Victron lithium iron phosphate (LiFePO₄)
battery
Each individual cell of a LiFePO₄ battery must be protected against over
voltage, under voltage and over temperature.
Victron LiFePO₄ batteries have integrated Balancing, Temperature and Voltage
control (acronym: BTV) and connect to the VE.Bus BMS with two M8 circular
connector cord sets.
The BTVs of several batteries can be daisy chained. Please see our LiFePO4
battery documentation for details.
The BMS will:
– shut down or disconnect loads in case of imminent cell under voltage,
– reduce charge current in case of imminent cell overvoltage or over
temperature (VE.Bus products, see below), and
– shut down or disconnect battery chargers in case of imminent cell
overvoltage or over temperature.
Protects 12V, 24V and 48V systems
Operating voltage range of the BMS: 9 to 70V DC.
Communicates with all VE.Bus products
The VE.Bus BMS connects to a MultiPlus, Quattro or Phoenix inverter with a
standard RJ45 UTP cable.
Products without VE.Bus can be controlled as shown below:
Note: AC Detector for MultiPlus and Quattro (included in VE.Bus BMS
delivery) not needed for MultiPlus-II models
Load Disconnect
The Load Disconnect output is normally high and becomes free floating in case
of imminent cell under voltage. Maximum current: 2A.
The Load Disconnect output can be used to control
– the remote on/off of a load, and/or
– the remote on/off of an electronic load switch (BatteryProtect, preferred
low power consumption solution).
Pre-alarm
The pre-alarm output is normally free floating and becomes high in case of
imminent cell under voltage (default 3,1V/cell, adjustable on the battery
between 2,85V and 3,15V per cell). Maximum current: 1A (not short circuit
protected).
The minimum delay between pre-alarm and load disconnect is 30 seconds.
Charge Disconnect
The Charge Disconnect output is normally high and becomes free floating in
case of imminent cell over voltage or over temperature. Maximum current: 10mA.
The Charge Disconnect output can be used to control
– the remote on/off of a charger and/or
– a Cyrix-Li-Charge relay and/or
– a Cyrix-Li-ct Battery Combiner.
LED indicators
– Enabled (blue): VE.Bus products are enabled.
– Cell>4V or temperature (red): charge disconnect output low because of
imminent cell over voltage or over temperature.
– Cell>2,8V (blue): load disconnect output high.
Load disconnect output low when off, due to imminent cell under voltage
(Vcell≤2,8V).
Safety instructions
Installation must strictly follow the national safety regulations in compliance with the enclosure, installation, creepage, clearance, casualty, markings and segregation requirements of the end-use application. Installation must be performed by qualified and trained installers only. Switch off the system and check for hazardous voltages before altering any connection.
- Do not open the Lithium Ion Battery.
- Do not discharge a new Lithium Ion Battery before it has been fully charged first.
- Charge only within the specified limits.
- Do not mount the Lithium Ion Battery upside down.
- Check if the Li-Ion battery has been damaged during transport.
Things to consider
3.1 Important warning
Li-ion batteries are expensive and can be damaged due to over discharge or
over charge.
Damage due to over discharge can occur if small loads (such as: alarm systems,
relays, standby current of certain loads, back current drain of battery
chargers or charge regulators) slowly discharge the battery when the system is
not in use.
In case of any doubt about possible 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. After
shutdown due to low cell voltage, a capacity reserve of approximately 1Ah per
100Ah battery capacity is left in the battery. The battery will be damaged if
the remaining capacity reserve is drawn from the battery. A residual current
of 10mA for example may damage a 200Ah battery if the system is left in
discharged state during more than 8 days.
3.2 AC Detector Li-ion software assistant for MultiPlus and Quattro (not
needed for MultiPlus-II models)
The AC Detector is a small add-on that can be built in a MultiPlus or Quattro
when used together with a LiFePO₄ battery and a VE.Bus BMS. Every VE.Bus BMS
is delivered with one AC Detector.
The purpose of the AC Detector is to restart the MultiPlus or Quattro when AC
supply becomes available, in case it has been switched off by the BMS due to
low cell voltage.
Without the AC Detector the MultiPlus or Quattro would remain off and
therefore would not start recharging the battery after shut down due to low
battery voltage.
The AC detector needs the Li-ion software assistant or the Self-consumption
ESS assistant to operate as intended.
Inverters (DC to AC only) with VE.Bus can be connected directly to the
MultiPlus/Quattro input of the BMS, no AC Detector or assistant needed.
3.3 DC loads with remote on/off terminals
DC loads must be switched off or disconnected in case of imminent cell under
voltage.
The Load Disconnect output of the VE.Bus BMS can be used for this purpose.
The Load Disconnect is normally high (equal to battery voltage) and becomes
free floating (= open circuit) in case of imminent cell under voltage (no
internal pull down in order to limit residual current consumption in case of
low cell voltage).
DC loads with a remote on-off terminal that switches the load on when the
terminal is pulled high (to battery plus) and switches it off when the
terminal is left free floating can be controlled directly with the Load
Disconnect output.
See appendix for a list of Victron products with this behavior.
For DC loads with a remote on/off terminal that switches the load on when the
terminal is pulled low (to battery minus) and switches it off when the
terminal is left free floating, the Inverting remote on-off cable can be used.
See appendix.
Note: please check the residual current of the load when in off state.
After low cell voltage shutdown a capacity reserve of approximately 1Ah per
100Ah battery capacity is left in the battery. A residual current of 10mA for
example may damage a 200Ah battery
if the system is left in discharged state during more than 8 days.
3.4 DC load: disconnecting the load with a BatteryProtect
A Battery Protect will disconnect the load when:
– input voltage (= battery voltage) has decreased below a preset value, or
when
– the remote on/off terminal is pulled low. The VE.Bus BMS can be used to
control the remote on/off terminal.
3.5 Charging the LiFePO₄ battery with a battery charger
Battery charging must be reduced or stopped in case of imminent cell over
voltage or over temperature.
The Charge Disconnect output of the VE.Bus BMS can be used for this purpose.
The Charge Disconnect is normally high (equal to battery voltage) and switches
to open circuit state in case of imminent cell over voltage.
Battery chargers with a remote on-off terminal that activates the charger when
the terminal is pulled high (to battery plus) and deactivates when the
terminal is left free floating can be controlled directly with the Charge
Disconnect output.
See appendix for a list of Victron products with this behavior.
Battery chargers with a remote terminal that activates the charger when the
terminal is pulled low (to battery minus) and deactivates when the terminal is
left free floating, the Inverting remote on-off cable can be used. See
appendix.
Alternatively, a Cyrix-Li-Charge can be used:
The Cyrix-Li-Charge is a unidirectional combiner that inserts in between a
battery charger and the LiFePO₄ battery. It will engage only when charge
voltage from a battery charger is present on its charge-side terminal. A
control terminal connects to the Charge Disconnect of the BMS.
3.6 Charging the LiFePO₄ battery with an alternator See figure 6.
The Cyrix-Li-ct is recommended for this application.
The microprocessor controlled Cyrix-Li-ct includes a timer and voltage trend
detection. This will prevent frequent switching due to a system voltage drop
when connecting to a discharged battery.
Installation
4.1 AC Detector for MultiPlus and Quattro (included in VE.Bus BMS delivery).
Not needed for MultiPlus-II models.
The purpose of the AC Detector is to restart the MultiPlus or Quattro when AC
supply becomes available, in case it has been switched off by the BMS due to
low cell voltage (so that it can recharge the battery).
Note 1: The AC Detector is not needed in case of an inverter.
Note 2: In systems consisting of several units configured for parallel,
three phase or split phase operation, The AC Detector should be wired in the
master or leader unit only.
Note 3: The VE.Bus BMS assistant or the Self-consumption ESS assistant
must be loaded in all units.
Installation procedure (see figure 3)
-
Connect the brown and blue input wires to the neutral and phase of the AC-in-1 input.
-
Quattro: connect the brown and blue output wires to the neutral and phase of the AC-in-2 input.
MultiPlus: no AC-in-2 input available. Please cut the AC2 wires close to the AC Detector
-
Use the short RJ45 UTP cable to connect the AC Detector to one of the two the VE.Bus sockets in the MultiPlus or Quattro (see figure 4).
-
Connect the VE.Bus BMS to the AC Detector with a UTP cable (not included).
-
A Digital Multi Control panel must be connected to the VE.Bus BMS. Do not connect a Digital Multi Control panel directly to a Multi or Quattro (signals from the control panel may be in conflict with signals from the VE.Bus BMS).
-
The ColorControl panel must be connected directly the Multi or Quattro.
4.2 Wire the system: see system examples below
Do not connect to the battery plus at this stage (alternatively: do not insert
the battery fuse(s)).
Important:
-
The UTP cable to the inverter or inverter/charger also connects the battery minus to the BMS.
In this case, in order to prevent ground loops, do not wire the battery minus connector of the BMS. -
Wire the positive supply input of the VE.Bus BMS to the system positive. A system on-off switch in the positive supply wire will disable the system when opened.
4.3 Battery
In case of several batteries in parallel and or series configuration, the two
M8 circular connector cord sets of each battery should be connected in series
(daisy chained).
Connect the two remaining cords to the BMS.
4.4. Powering up
In case of a DC only system: connect the battery plus. The system is now ready
for use.
In case of a system with Multis, Quattros or inverters with VE.Bus:
4.4.1. After completion of the installation, disconnect the BMS from the
VE.Bus and replace by a Victron Interface MK2 and a computer.
4.4.2. Connect the battery plus.
4.4.2. Configure inverter/charger(s) or inverter(s) for parallel or three
phase configuration if applicable.
Inverter/chargers: the AC Detector should be installed only in the master or
leader of a parallel or three phase system.
Inverters: AC detector not needed.
4.4.3. Load the VE.Bus BMS assistant or a ESS assistant in all units (must be
done for each unit separately)
4.4.4. Remove the MK2 and reconnect to the BMS.
4.4.5. The system is now ready for use
System examples
Note: the BMS is connected to the battery minus by the UTP cable between
the BMS and the inverter/charger.
Therefore, in order to prevent ground loops, do not wire the BMS minus
connector.
Note: in this case the battery minus of the BMS must be wired.
Note: the BMS is connected to the battery minus by the UTP cable between
the BMS and the inverter/charger.
Therefore, in order to prevent ground loops, do not wire the BMS minus
connector.
Note 1: the AC Detector is installed in the leader only.
Note 2: the BMS is connected to the battery minus by the UTP cable
between the BMS and the inverter/charger.
Therefore, in order to prevent ground loops, do not wire the BMS minus
connector.
To charge the starter battery: use a DC-DC converter or a small battery
charger connected to the Multi or Quattro.
Alternators which need DC voltage on the B+ output to start charging can be
started by pushing the Start Assist push button once the engine is running.
Note: the BMS is connected to the battery minus by the UTP cable between
the BMS and the inverter/charger.
Therefore, in order to prevent ground loops, do not wire the BMS minus
connector.
Note: the BMS is connected to the battery minus by the UTP cable between
the BMS and the inverter/charger.
Therefore, in order to prevent ground loops, do not wire the BMS minus
connector.
Frequently asked questions
Q1: I have disconnected the VE.Bus BMS, and now my Multi or Quattro will not switch on, why?
A Multi or Quattro programmed with the VE.Bus BMS assistant, and unable to find a VE.Bus BMS on the bus, will go into an emergency mode. In this mode it will charge the batteries with 5 Ampère max, up to 12V, 24V or 48V, depending on system voltage. Note that in this mode, the only LED which is on is the Mains On LED. If you disconnect the AC input from the Multi/Quattro, it will switch off. It will not start to invert since it cannot get verification on the battery health from the VE.Bus BM Note that, when the batteries are depleted or disconnected, Quattros need to be powered from AC input 1. Supplying power toAC Input 2 will not make a Quattro switch on and start charging.
Q2: The batteries are empty and the Multi/Quattro will not start to charge, how to get the system up and running again.
When lithium batteries are depleted (the voltage is around 9V or even lower) the battery voltage might be below the operating window of the VE.Bus BMS. In that case the VE.Bus BMS will not be able to start the Multi/Quattro, even if an AC Detector is installed. To start the system again, disconnect the VE.Bus BMS from the Multi, and refer to Q1. Note that it might be necessaryto disconnect any Blue Power Panels, NMEA2000 interfaces or other similar smart products. As long as they are not switched on themselves, they can prevent the Multi/Quattro from starting up. A simpler option to revive a depleted system might be to connect a small battery charger, for example 5 Ampère, and wait for the battery voltage to get back up to 12 Volt.
Q3: What happens with the Multi/Quattro when the BMS gives a low cell voltage signal?
The Multi/Quattro will be in charger only mode: when AC input is present, it will charge the batteries. And when the AC input is not present, it will switch off.
Q4: What happens with the Multi/Quattro when the BMS gives a high cell voltage signal?
The high cell voltage signal will only be given when there are unbalanced cells. The Multi/Quattro will switch to bulk, and starts charging with a reduced charge current. This allows the balancing system to rebalance the cells.
Specifications
VE.Bus BMS|
---|---
Input voltage range| 9 – 70VDC
Current draw, normal operation| 10mA (excluding Load Disconnect current)
Current draw, low cell voltage| 2mA
Load Disconnect output| Normally high (output voltage ≈ supply voltage –
1V) Floating when load needs to be disconnected Source current limit: 2A
Sink current: 0A
Charge Disconnect output| Normally high, (output voltage ≈ supply
voltage – 1V) Floating when charger should be disconnected Source current
limit: 10mA
Sink current: 0A
GENERAL
VE.Bus communication port| Two RJ45 sockets to connect to all VE.Bus products
Operating temperature| -20 to +50°C 0 – 120°F
Humidity| Max. 95% (non-condensing)
Protection grade| IP20
ENCLOSURE
Material and colour| ABS, matt black
Weight kg| 0,1
Dimensions (hxwxd) in mm| 105 x 78 x 32
STANDARDS
Standards: Safety
Emission Immunity
Automotive Directive| EN 60950
EN 61000-6-3, EN 55014-1
EN 61000-6-2, EN 61000-6-1, EN 55014-2
EN 50498
Cyrix Li-ion ct (see Cyrix Li-ion datasheet for more information)|
12/24-120| 24/48-120
---|---|---
Continuous current| 120A|
Connect voltage| From 13,7V to 13,9V and 27,4V to 27,8V with intelligent trend
detection|
Disconnect voltage| From 13,2V to 13,4V and 26,4V to 26,8V with intelligent
trend detection|
Start Assist
| Yes (The Cyrix remains engaged during 15 seconds after the control input has
been pulled twice to battery minus.)|
Cyrix Li-ion load| 12/24-120| 24/48-120
**** Please use a Battery Protect instead: much lower power consumption
Cyrix Li-ion Charge| 12/24-120| 24/48-120
Continuous current| 120A| 120A
Connect voltage
| Engages when voltage on the charger side exceeds 13,7V to 13,9V and 27,4V to
27,8V with intelligent trend detection| Engages when voltage on the charger
side exceeds 27,4V to 27,8V and 54,8V to 55,6V with intelligent trend
detection
Disconnect voltage| From 13,2V to 13,4V and 26,4V to 26,8V with intelligent
trend detection| From 26,4V to 26,8V and 52,8V to 53,6V with intelligent trend
detection
Charge not active detection| The Cyrix disengages every hour and remains open
in case of low voltage on the charger side
General| 12/24-120| 24/48-120
Over voltage disconnect| 16V / 32V| 32V / 64V
Over temperature disconnect| Yes
Current consumption when open| <4mA
Current consumption when closed| <220mA / < 110mA| < 110mA / <60mA
Operating temperature range| -20 to +50°C
Protection category| IP54
Weight kg (lbs)| 0,11 (0.24)
Dimensions h x w x d in mm (h x w x d in inches)| 46 x 46 x 80 (1.8 x 1.8 x
3.2)
Appendix:
Loads which can be controlled directly by the Load Disconnect output of the
BMS
Inverters:
All Phoenix inverters VE.Direct 250/375/500/800/1200
Phoenix 12/800 Phoenix 24/800
Phoenix 12/1200 Phoenix 24/1200
Phoenix 48/800 Phoenix 48/1200
DC-DC converters:
All Tr type DC-DC converters
Orion 12/24-20
Orion 24/12-25
Orion 24/12-40
Orion 24/12-70
Loads for which a Inverting remote on-off cable is needed
(article number ASS030550100)
Inverters:
Phoenix 12/180
Phoenix 24/180
Phoenix 12/350
Phoenix 24/350
All Phoenix inverters rated at 3kVA and more
For Skylla TG battery chargers a Non inverting remote on-off cable Is needed
(article number ASS030550200)
For Skylla-i battery chargers a Skylla-i remote on-off cable Is needed
(article number ASS030550400)