General Description; Safety Instructions; Things To Consider - Victron energy VE.Bus BMS Manual

1. 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 BTV's 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 12 V, 24 V and 48 V systems
Operating voltage range of the BMS: 9 to 70 V 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:
Load Disconnect
The Load Disconnect output is normally high and becomes free floating in case of imminent cell under voltage. Maximum
current: 2 A.
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) and/or
- a Cyrix-Li-load relay.
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: 10 mA.
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).

2. 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 or on the side.
• Check if the Li-Ion battery has been damaged during transport.

3. Things to consider

3.1 AC Detector for MultiPlus and Quattro
The AC Detector is a small add-on that has to be built in a MultiPlus or Quattro when used together with a LiFePO₄ battery and
a VE.Bus BMS.
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).
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.
Inverters (DC to AC only) with VE.Bus can be connected directly to the MultiPlus/Quattro input of the BMS, no AC Detector
needed.
3.2 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.
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