1. Introduction
1.1. The Lynx Smart BMS NG
The Lynx Smart BMS NG is a dedicated Battery Management System for Victron Lithium NG (not to be confused with the Lynx Smart BMS 500A, which is for Victron Smart Lithium batteries) batteries available with a nominal voltage of 12.8V, 25.6V and 51.2V in various capacities. This is the safest of the mainstream lithium battery types. The maximum number of batteries in one system is 50, which results in a maximum energy storage of 192kWh in a 12V system and up to 384kWh in a 24V and 48V system. The maximum energy storage capacity can be multiplied by paralleling multiple Lynx Smart BMSs, which also ensures redundancy should one battery bank fail.
Multiple BMS-es are available for our Lithium NG series of batteries, and the Lynx Smart BMS NG is the most feature-rich and complete option. Its main features are:
Built-in 500A or 1000A contactor used as a fallback safety mechanism and also suitable as a remote controllable main system switch.
Battery monitor, indicating state of charge percentage and more data.
Pre-alarm signal: provides a warning before the system shuts down due to a low cell voltage.
Bluetooth for use with our VictronConnect App, for setup, monitoring and diagnostic.
Local and remote monitoring using a Victron GX device, for example, the Cerbo GX and our VRM portal.
M10 busbar - The Lynx Smart BMS NG integrates seamlessly into our Lynx Distributor system and can be connected to all Lynx M10 products.
 Lynx Smart BMS NG 500A |  Lynx Smart BMS NG 1000A |
1.2. Features
Battery Management System
The BMS monitors, controls, and protects your Victron Lithium NG batteries. It detects the state of charge and protects against deep discharge and overcharging.
Its main features are:
Pre-alarm mode configurable via the programmable relay
ATC/ATD ports to control chargers and loads
DVCC closed loop control for compatible Victron inverter/charger, Orion XS DC-DC battery charger and MPPTs via a connected GX device
Discharge floor used to set the minimum SoC to determine how far the battery is allowed to be discharged
A pre-alarm warns with a minimum delay of 30 seconds of an imminent shutdown of the loads as a result of an impending low cell voltage. By reacting quickly on the pre-alarm, for example, by reducing the load or starting a generator to charge the batteries, the shutting down of the loads can be prevented.
The ATC contact is opened to stop charging at a high cell voltage or low temperature, while the ATD contact is opened to stop discharging at a low cell voltage.
DVCC controls compatible devices via Lynx Smart BMS NG and a connected GX device with the advantage of no additional wiring or configuration for those devices. Charging current and voltages are set automatically, thus Bulk, Absorption and Float algorithms are no longer used. Charging or discharging are stopped at low or high cell voltage or low temperature. For more information about DVCC, please check the GX device manual.
Contactor
The built-in contactor serves two purposes:
It acts as a secondary safety system to protect the battery in case the primary controls (ATC and ATD contacts as well as DVCC) fail to disable the loads and/or chargers when required.
It can be used as a remote controlled main system on/off switch via the VictronConnect app, a GX device (only Standby and On), as well as using the Remote on/off terminals.
Built-in pre-charge circuit
The built-in pre-charge circuit pre-charges capacitive loads such as inverters or inverter/chargers before the contactor closes to prevent high inrush current.
Battery Monitor
The Lynx Smart BMS NG battery monitor operates in a similar fashion as the other Victron Energy battery monitors. It contains a shunt and battery monitor electronics. Readout of the battery monitor data is via Bluetooth using the VictronConnect App or a GX device and the VRM portal.
Programmable relay
The Lynx Smart BMS NG has a programmable relay that can be used as an alarm relay (combined with the pre-alarm) or to shut down an alternator via its external regulator (ignition wire).
AUX terminal
The Lynx Smart BMS NG is equipped with an auxiliary power supply. This supply outputs the same voltage as the system battery voltage and is rated at a maximum continuous current rating of 1.1A.
The purpose of the auxiliary power supply is to keep certain systems powered, for example a GX device, after the BMS has turned off loads in case of a low cell voltage event.
Note
It is recommended that the system includes a GX device powered by the AUX port. This keeps the GX device supplied with power until the AUX port is finally switched off (max. 5 minutes after a low cell voltage event) to preserve energy for battery self-discharge.
Parallel redundant Lynx Smart BMS
The new parallel redundancy feature for the Lynx Smart BMS and Lynx Smart BMS NG series allows multiple Lynx BMSes in one installation. Each has its own battery bank, and together they form a single redundant battery system. Up to 5 BMS-es can be paralleled. For more details, please see the Paralleling Lynx Smart BMSes chapter.
1.3. Communication and interfacing
The Lynx Smart BMS NG communicates via various interfaces with other devices and services. The following list provides an overview of the most important interfaces:
Bluetooth: to change settings and monitor the Lynx Smart BMS NG via our VictronConnect App.
Note that Bluetooth can be disabled via VictronConnect or a GX device but can only be re-enabled from a GX device.
VE.Can: to connect a GX device to the Lynx Smart BMS NG. The GX device will show all measured parameters, operational state, battery SoC, cell voltages and temperatures, and alarms, and make them available to be controlled via our remote monitoring VRM portal.
Lynx Distributor fuse monitoring: via our VictronConnect app and a connected GX device. Communication with the Lynx Distributors is via its RJ10 connectors. The Lynx Smart BMS NG can be used to read out the Lynx Distributors, generate alarms in case a fuse is blown or communication is lost. Fuse status communication requires Lynx Distributor with serial number HQ1909 or later.
NMEA 2000 via VE.Can: Communication to an NMEA 2000 network can be established via VE.Can using a VE.Can to NMEA2000 micro-C cable. See the Supported NMEA 2000 PGNs in the appendix for more information.