7. Troubleshooting and Support
Consult this chapter in case of unexpected behaviour or if you suspect a product fault.
The correct troubleshooting and support process is to first consult the common issues as described in this chapter and the Appendix section 10.1. LED indications, warnings, alarm and error codes.
Should this fail to resolve the issue, contact the point of purchase for technical support. If the point of purchase is unknown, refer to the Victron Energy Support webpage.
7.1. How to recover from OFF mode when no charge voltage was detected
This chapter explains how to turn on the BMS (thereby activating the system again) after the BMS has switched to OFF mode when no charge voltage has been detected for 5 minutes after a low cell voltage event or a low SoC shutdown.
Background:
If, after a low cell voltage or low SoC event, the BMS does not detect a charge voltage within 5 minutes, the BMS will enter OFF mode. In OFF mode, the ATC and ATD contacts are open, and all interfaces except Bluetooth are turned off to conserve energy. All chargers and loads turn off when the ATC and ATD contacts open. If, at a later stage, the chargers in the system are powered by the grid or a generator, they will still remain off because the BMS is not generating the ATC signal.
There are two ways to make the BMS leave the OFF state so that the system will power up:
Connect an external charger to the system. The BMS will resume normal operation and close the contactor when it detects a charge voltage on the system side of the BMS.
Use the Remote on/off switch or the soft switch in the VictronConnect app as described in the next paragraph.
Force the BMS out of OFF mode:
To force the BMS out of OFF mode, switch the BMS Remote on/off switch or the soft switch in the VictronConnect app off for 5 seconds and then switch it back on or unplug the 11-pin multi connector from its socket and reinsert it after 5 seconds.
The BMS will activate and close its contactor so that the battery is again connected to the system, even though the battery voltage might be too low. The BMS will close the ATC and ATD contacts, provided that the battery allows this. However, in case of an empty battery, the ATD contact will stay open, and only the ATC contact will close.
As soon as the ATC contact is closed, the system's chargers reactivate and start charging the battery.
Once the battery is sufficiently charged, the ATD contact will close, and the loads will reactivate.
Note
Note that if no sufficient charge voltage (check the BMS operating mode chapter for charge voltages) is detected within 5 minutes, the BMS will enter OFF mode again. In this case, you will have to restart the procedure as described above. Make sure beforehand that a sufficient charge source is available.
Please also note that the above procedure is not required when DVCC-controlled chargers are present in the system. They will charge for a few minutes, or MPPT chargers will stay on regardless of whether the GX device and/or ATC status is off.
7.2. Lynx Smart BMS NG does not power up
This can be caused by one of the following reasons:
No battery supply
No LEDs are illuminated on the Lynx Smart BMS NG. Check the battery supply voltage. Check cables and fuses on the battery side. It could also be that the Lynx Smart BMS NG is in OFF mode. For more info on that, see paragraph Powering up [29].
Reverse battery supply
Check the polarity of the supply voltage into the Lynx Smart BMS NG. If it is reversed, correct the polarity mistake. The unit should now power up.
No charge voltage detected for 5 minutes after a low cell voltage, low SoC or low-temperature event
Ensure that a charger is connected and switched on. The battery temperature must be at least 5 °C to be allowed to charge.
Remote on/off switched off or wire loop missing
The Remote on/off switch must be turned on, or a wire loop must be inserted between pin 10 and pin 11 of the multi-connector. Check that the multi-connector is correctly seated.
Soft Switch turned off in VictronConnect App
Switch the system to ON mode using the soft switch in the VictronConnect app.
System in Standby mode
Switch the system to ON mode using the soft switch in the VictronConnect app or a connected GX device.
Battery voltage issues
The Lynx Smart BMS NG, on the first installation, will auto-detect the battery voltage and set it to either 12V, 24V or 48V. Each set voltage has a specific battery voltage range (threshold). If the Lynx Smart BMS measures a voltage that is outside this threshold, one of these alarms will be generated:
Probably wrong system voltage - red LED flashing 7 times every 4 seconds.
Battery voltage not allowed - red LED flashing 14 times every 4 seconds.
To fix this, check the battery settings or check the battery voltage.
This table indicates the voltage thresholds for each system voltage:
System voltage | Voltage threshold |
|---|---|
12V | 9V - 15V |
24V | 16V - 30V |
48V | 32V - 60V |
Pre-charge errors
There are two specific errors that can be generated during the pre-charge process:
Pre-charge high current: The red LED flashes six times every four seconds, indicating that the pre-charged energy or current has been exceeded.
Pre-charge timeout: The red LED flashes five times every four seconds, indicating that the pre-charge process has taken too long to complete.
Pre-charge faults are mostly caused by:
A short circuit on the load output – potentially caused by a malfunctioning load or if there is a wiring issue like a short circuit.
Loads with a too-high capacitance or too-low resistance (less than 20 Ohm) have been connected to the load output.
To fix these errors, turn off or remove some loads or chargers and rule out wiring problems or shorts.
Internal error
Contact your Victron supplier if one of the following errors are occurring:
Internal supply error - Red LED flashing 12 times every 4 seconds
Initialisation error - Red LED flashing 9 times every 4 seconds
Contactor failure - Red LED flashing 10 times every 4 seconds
Hardware error - GX device alarm calibration lost - GX device alarm
7.3. Lynx Smart BMS NG operational issues
High discharge current
A high current alarm is triggered if the current exceeds 600 A (1200 A) for longer than 5 minutes. The red LED flashes eight times every four seconds. Reduce the loads connected to the Lynx Smart BMS NG so that the current through the BMS is below 500 A (1000 A).
High charge current
A high current alarm is triggered if the current exceeds 600 A (1200 A) for longer than 5 minutes. The red LED flashes eight times every four seconds. Turn chargers off so the current through the Lynx Smart BMS NG will be below 500 A (1000 A).
Contactor (relay) issues
The Lynx Smart BMS NG has three guards to protect the contactor.
Overcurrent protection: an alarm is generated when the current exceeds 600 A (1200A) for 5 minutes.
Contactor voltage monitoring: an alarm is generated when the voltage over the contactor is higher than 0.5V. A high voltage indicates high resistance and high power dissipation, indicating a bad contactor.
Electrical/mechanical protection: Two thermal switches are mounted on the busbar. The contactor opens, and an alarm is generated when the busbars' temperature exceeds 130 °C.
High BMS temperature
Check ambient temperature and check if the two built-in fans are running. Reduce the ambient temperature.
Settings invalid
Settings data is corrupt. Reset to factory defaults.
7.4. BMS issues
7.4.1. The BMS frequently disables the battery charger
A balanced battery will not switch off the charger even if it is fully charged. However, if the BMS switches the charger off frequently, this indicates an imbalance in the cells.
In case of moderate or large cell imbalance, it is expected behaviour that the BMS frequently disables the battery charger. This is the mechanism behind this behaviour:
As soon as one cell reaches 3.60V, the BMS disables the charger due to high cell voltage. Whilst the charger is disabled, the cell balancing process still continues, moving energy from the highest cell into adjacent cells. The highest cell voltage drops, and as soon as it falls below 3.6V, the charger is activated again. This cycling typically takes between one and three minutes. The voltage of the highest cell will rise again quickly (this can be in a matter of seconds), after which the charger will be disabled again and so forth. This does not indicate a problem with the battery or the cells and will continue with this behaviour until all cells are fully charged and balanced. This process might take several hours, depending on the level of imbalance. In case of serious imbalance, this process can take up to 12 hours. Balancing will continue throughout this process and balancing even takes place when the charger is disabled. The continued enabling and disabling of the charger can appear strange, but rest assured that there is no problem. The BMS merely protects the cells from overvoltage.
7.4.2. The BMS displays an alarm even though all cell voltages are within range
A loose or damaged BMS cable or connector is a possible cause. Check all BMS cables and their connections.
Also consider that once a cell undervoltage alarm has occurred, the cell voltage of all cells needs to be increased to 3.2V before the BMS clears the undervoltage alarm.
A way to rule out if a fault is originating from a faulty BMS or a faulty battery is to check the BMS using one of the following BMS test procedures:
Single battery and BMS check:
|  |
Multiple batteries and BMS check:
Bypass one of the batteries by disconnecting both its BMS cables.
Connect the BMS cables of the neighbouring batteries (or battery and BMS) to each other, effectively bypassing the battery.
Check if the BMS has cleared its alarm.
Repeat this for the next battery if the alarm has not been cleared.
The BMS is faulty if the alarm is still active after all batteries have been bypassed.
If the BMS clears its alarm when a particular battery is bypassed, that particular battery is faulty.
Eliminating a BMS error by bypassing a suspect battery
7.4.3. How to test if the BMS is functional
To test if the BMS is functional, disconnect one of the battery BMS cables and see if the BMS will go into alarm mode.
Check BMS functionality by deliberately loosening a BMS cable
7.4.4. System in OFF mode
This is indicated by the status LED off and the Bluetooth LED flashing every three seconds.
The Lynx Smart BMS NG goes into OFF mode once a low cell voltage event occurs and no charge voltage has been detected for 5 minutes to conserve as much power as possible. Bluetooth is still active, but other non-essential interfaces are turned off, including the power to the Lynx Distributor(s).
Check the cell voltages of the connected batteries, and if they are low, charge them. As soon as the Lynx Smart BMS NG sees a charge voltage, it will automatically reactivate and close its contactor to allow battery charging.
7.4.5. ATC/ATD is missing
Error #36 (ATC/ATD error) occurs when the discharge current is > 1.5A while ATD is disabled or when the charge current is > 1A while ATC is disabled.
This can be caused by loads or chargers that are not controlled by ATC/ATD.
Ensure all loads and chargers are controlled by ATC/ATD (if not controlled by DVCC).
7.5. Battery monitor issues
7.5.1. Incomplete current reading
The negatives of all loads and charge sources in the system must be connected to the system load side of the shunt, which is the right side of the BMS in normal position.
If the negative terminal of a load or charging source is connected directly to the battery negative terminal or the “battery negative” side of the shunt, its current will not flow through the battery monitor. It will, therefore, not be taken into account, resulting in a wrong SoC reading.
7.5.2. Incorrect state of charge reading
Incorrect state of charge due to a synchronisation issue:
The synchronisation process is automatic and is performed each time the battery is fully charged. The battery monitor determines that the battery is fully charged when all 3 "charged" conditions have been met. The "charged" conditions are:
Charged voltage (Voltage)
Tail current (% of battery capacity)
Charge detection time (minutes)
Practical example (default battery monitor settings and a 12.8V 200Ah Lithium NG battery) for the conditions that must be met before synchronisation takes place:
The battery voltage has to be 14.0V (28.0V, 56.0V)
The charge current has to be less than 0.04 x battery capacity (Ah). For a 200Ah battery this is 0.04 x 200 = 8A
Both of the above conditions must be stable for 3 minutes
If the battery is not fully charged or if automatic synchronisation does not happen, the state of charge value will start to drift and eventually not represent the battery's actual state of charge.
The SoC can also be synchronised and set manually via the VictronConnect app.
7.5.3. Synchronisation issues
If the battery monitor does not synchronise automatically, there is a possibility that the battery will never reach a full state of charge. Fully charge the battery and check whether the charge level finally displays 100 %.
Another option is to lower the setting for the Charged voltage and/or increase the setting for the Tail current.
It is also possible that the battery monitor synchronises too early. This can happen in solar systems or systems with fluctuating charge currents. If this is the case, try to decrease the Charged voltage, Tail Current, and Charged detection time settings slightly.
7.6. VictronConnect issues
Interrupted firmware update
This is recoverable. Just try to update the firmware again.
7.7. GX device issues
This chapter only describes the most common issues. If this chapter does not solve your issue, consult the manual of the GX device.
Incorrect CAN-bus profile selected
Check that VE.Can is set to use the correct CAN-bus profile. On your GX device, navigate to Settings/Services/VE.Can port and check if it is set to "VE.Can & Lynx Ion BMS (250kbit/s)".
Also make sure that the Lynx Smart BMS NG is connected to the VE.Can port of your GX device and not the BMS-Can port (e. g. on a Cerbo GX).
RJ45 terminator or cable issue
VE.Can devices connect in "daisy chain" to each other and a RJ45 terminator needs to be used with the first and last device in the chain.
When connecting VE.Can devices, always use "manufactured" RJ45 UTP cables. Do not manufacture these cables yourself. Faulty homemade cables cause many communication and other seemingly unrelated product issues.