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Lynx Smart BMS

6. Configuration and settings

In this section:

6.1. Power up for the first time

The Lynx Smart BMS will power up when a battery is connected and the wire loop is placed in between pin 10 and 11 of the multi connector or the Remote on/off switch is switched on.

On first power up and after a "Reset to defaults" (via VictronConnect app), the Lynx Smart BMS automatically determines and sets these settings:

  • System voltage, 12, 24 or 48V, by measuring the battery voltage.

  • Pre-alarm support in the batteries.

The settings can also be reviewed and changed manually.

6.2. Update firmware

A firmware update of the Lynx Smart BMS can be performed in two different ways:

  • Via the VictronConnect app

  • Via the VRM: Remote Firmware Update feature (requires an internet connected GX device)

Notes on firmware updating in general

  • Newer is not always better

  • Don't break it if it works

  • Be sure to read the changelog before starting the update process. The changelog can be downloaded from Victron Professional.

Therefore: use this feature with care. Our main advice is not to update a running system unless there are problems with it or before the first startup.

Notes on updating the Lynx Smart BMS firmware

  • A firmware update will not result in a temporary system shutdown. During the update, the Lynx Smart BMS keeps all contacts and the contactor in the same state as when starting the update. If the update fails, ATD/ATC and contactor open after 120 seconds, for safety reasons. This also gives time to try updating again.

  • Updating the firmware always starts a new full charging cycle despite the SoC threshold setting, which means that the charge voltage limit (CVL) is automatically adjusted from 13.5V to 14.2V (for a 12V system).

  • In case of a new installation, it is also recommended to check and update the firmware of each connected lithium battery.

Updating firmware via VictronConnect

Please note the following before performing a firmware update via VictronConnect:

  1. For detailed instructions on how to update the firmware, see the firmware update chapter in the VictronConnect manual.

  2. If there is a newer firmware version available, the VictronConnect app (make sure the VictronConnect app is the latest version) will notify you of this as soon as a connection with the Lynx Smart BMS is made.

Updating firmware via VRM: Remote firmware update


  • Remotely update internet-connected products straight from the VRM Portal

  • No need to install any software

  • Works from laptop, tablet & phone

  • No need to find the right firmware file: the system has all, and will clearly indicate that a newer version is available.

See the VRM: Remote firmware update manual for detailed instructions.

6.3. Lynx Smart BMS settings

Once powered up, use the VictronConnect app to configure the BMS settings.

Check the Battery voltage setting (12, 24 or 48V):

  • This will have been detected automatically, double check it.

Set the Battery capacity setting:

  • Enter the total battery bank capacity of the connected battery. Caution, for batteries connected in series, do not add the capacity of each battery to determine the total capacity of the bank.

  • Check out our book Wiring Unlimited section 3.1 to learn how to determine battery capacity.


If the battery capacity input is incorrect, the SoC will also be incorrectly calculated. Make sure the battery capacity calculation is correct.

Set the Number of batteries in parallel :

  • Enter the number of paralleled batteries in the system.


The wrong number of parallel batteries will lead to a miscalculation of the balancing algorithm. Make sure this value is entered correctly.

Check the Pre-alarm mode setting:

This setting is automatically configured upon initial power-up and after a "Reset to defaults". It is enabled by default.

  • enabled: recommended setting. A visual or audible device linked to the programmable relay is activated in case of a pre-alarm.

  • disabled: If disabled, it will ignore the discharge current limit at pre-alarm setting.


Older Victron Lithium Batteries Smart manufactured before 2019/2020 do not have the pre-alarm signal. Nevertheless, the Lynx Smart BMS also generates the pre-alarm signal for these batteries with the restriction that the threshold for this is derived from the undervoltage alarm setting (in the battery) of 2.6V - 2.8V. The undervoltage alarm then occurs with a fixed delay of 30 seconds after pre-alarm.

Set the Relay setting:

The programmable relay has two operation modes: Alarm relay and Alternator ATC.

  • When set to Alarm relay mode, the Alarm relay setting becomes active and continuous or intermittent operation can be selected. In intermittent operation the relay switches on and off every 0.8 seconds.

  • When configured for Alternator ATC mode, the relay will only activate when the contactor is closed. Before the contactor is opened, Alternator ATC is opened first and 2 seconds later the contactor. These 2 seconds ensure that the alternator regulator is switched off before the battery is disconnected from the system.

DVCC settings:

DVCC is forced on and cannot be turned off. However, a few settings can be changed, which are described below.

Please note that these settings only affect compatible DVCC devices such as Victron inverter/chargers and Solar MPPT chargers.

  • Discharge Current Limit at pre-alarm (default "No"): if set to "Yes", the discharge current limit is already set to 0A in the event of a pre-alarm, while the ATC contact remains closed. In this way it’s possible to save some battery power for essential DC loads, for example on boats such as lighting, bilge pump and navigation.

  • Absorption time: is set to 2 hours by default. This can be adjusted if necessary.

  • Repeated absorption interval: in days at which a new full charging cycle is started, if the battery SoC does not fall below the SoC threshold. The default is every 30 days and can be adjusted if required.

  • SoC threshold: is set by default to 70%. This is the threshold at which the Lynx Smart BMS starts a new full charging cycle. This can be adjusted if required.

    A new charge cycle means that the CVL (charge voltage limit) is increased from 13.5V (for a 12V battery) to 14.2V.

    In addition to the SoC threshold, a new charging cycle is started after a firmware update, when the battery voltages are below 12V/24V/48V (3V per cell) or when a low cell voltage is detected.

Battery monitor settings:

Unlike other battery monitors, the Lynx Smart BMS battery monitor settings are mostly fixed settings and are not customisable. The reason for this is that the Lynx Smart BMS is always used together with Victron Lithium Batteries Smart and a lot of battery monitor parameters are therefore known because they relate to the battery type.

The following settings are adjustable. A full list of all settings used can be found in the Appendix section 10.3.

  • Charged voltage: the voltage at above which the battery monitor synchronises and resets the SoC to 100%. For synchronisation to happen, the tail current and charged detection time conditions need to have been met as well. The default is set to 14.0V and can be adjusted if necessary. In case the system voltage setting is changed, the charged voltage setting needs to be adjusted as well.

  • Tail current: the current at below which the battery monitor synchronises and resets the SoC to 100%. For synchronisation to happen, the charged voltage and charge detection time conditions need to have been met as well. The default is set to 4% and can be adjusted if needed.

  • Charged detection time: is the time passed after which the battery monitor synchronises and resets the SoC to 100%. For synchronisation to happen, the charged voltage and tail current conditions need to have been met as well. The default is set to 3 minutes and can be adjusted if necessary.

  • Discharge floor: this parameter has two functions:

    • Its primary use is to set the minimum SoC to determine how far the battery may be discharged and to ensure that there is enough energy left for self-discharge after a low SoC shutdown.

      A limited depth of discharge is good for battery health, but also provides backup power to keep the system running, e.g. until sunrise for solar systems.

      When the set discharge floor is reached, a low SoC alarm will be issued. The BMS then switches to OFF mode with a delay of 5 minutes if no sufficient charge voltage has been detected on the system side of the BMS by then.

      Setting the discharge floor to zero (not recommended), disables this feature.


      The discharge floor prevents full discharge and should be chosen so that there is always enough energy in the battery for self-discharge before the battery can be recharged.

      Example: A 10% discharge floor still provides enough stored energy for the self-discharge of a 200Ah battery to last about 9 months without recharging.

    • It is used in the calculation for the 'Time remaining' or 'Time-to-go' value displayed in the VictronConnect app, a connected GX device or on the VRM portal. The battery monitor uses the actual discharge current to calculate the time it takes to reach the set discharge floor.

  • Low SoC warning level: the level at which a warning is issued before the discharge floor has been reached.

  • State of charge: manually set the current state of charge.

  • Synchronise SoC to 100%: manually synchronise SoC to 100%.


VictronConnect settings Lynx Smart BMS

6.4. Lynx Distributor settings

These instructions only apply if the system contains one or more Lynx Distributors.

Each Lynx distributor must be addressed and set to A, B, C or D. This is done via a 2-way dip switch located inside the Lynx Distributor. Refer to chapter 6.1.3. Addressing Lynx Distributor in the Lynx distributor manual.

Use the VictronConnect app to give each fuse a custom name (maximum 16 characters). If the fuse name is empty (0 characters), the fuse will be disabled and ignored for monitoring.

  1. Navigate to the Settings page by clicking the cog wheel icon at the top right hand corner.

  2. On the Settings page scroll down to the Lynx Distributor settings.

  3. Tap on a distributor name. A new menu opens with all 4 fuses.

  4. Tap on a fuse to assign a custom name and/or to disable the fuse manually from monitoring.