Lynx Smart BMS 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: there are 2 thermal switches mounted on the busbar. The contactor opens and an alarm is generated when the temperature of the busbars becomes higher than 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. 9.4. BMS issues 9.4.1.
The BMS frequently disables the battery charger A well-balanced battery does not disable the charger, even when the batteries are fully charged. But when the BMS frequently disables the charger, this is an indication of cell imbalance. In case of moderate or large cell imbalance it is an expected behaviour that the BMS frequently disables the battery charger. This is the mechanism behind this behaviour: As soon as one cell reaches 3.75V, 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 is merely protecting the cells from over voltage. 9.4.2. The BMS is prematurely turning loads off This could be because of a cell imbalance. If a cell voltage falls below the "Allowed-to-Discharge cell voltage" setting in the battery (default 2.8V), the BMS will turn the loads off. Check the cell voltages of all batteries that are connected to the BMS using the VictronConnect app.
Also check if all batteries have the same "Allowed-to-Discharge cell voltage" settings. Once the loads have been turned off due to low cell voltage, the cell voltage of all cells needs to be 3.2V or higher before the BMS will turn the loads back on. 9.4.3. The pre-alarm setting is missing in VictronConnect Pre-alarm is only available if the battery supports it. The current battery models all support it, but older batteries do not have the hardware required for the pre-alarm feature. 9.4.4. BMS is displaying alarm while all cell voltages are within range A possible cause is a loose or damaged BMS cable or connector. Check all BMS cables and their connections.
Also consider that once there has been a cell under voltage alarm, the cell voltage of all cells need to be increased to 3.2V before the battery clears the under voltage alarm. A way to rule out if a fault is originating from a faulty BMS or from a faulty battery is to check the BMS using one of the following BMS test procedures: Single battery and BMS check: Disconnect both BMS cables from the BMS. Connect a single BMS extension cable between both BMS cable connectors. The BMS cable should be connected in a loop, as in below diagram. The loop tricks the BMS in thinking that there is a battery connected without any alarms.
If the alarm is still active after the loop has been placed, the BMS is faulty. If the BMS cleared the alarm after the loop has been placed, the battery is faulty and not the BMS. Page 34 Troubleshooting and Support