This page helps solving the most common issues of the MG SmartLink MX. The following situations are described on this page:
- Status indication
- SmartLink MX is not able to detect BMSs
- Combined BMS does not start due to voltage difference
Always make sure that the observations are matching the description in the Diagnose section before trying to solve it.
Always consult the manual before using the MG SmartLink MX.
For more information about configuring a battery system or settings, visit the SmartLink MX User Guide page.
All solutions given on this page are based on the most common issues. In case that the correct solution cannot be found below, please contact us via our website or by sending a Support Request.
¶ Related pages
- Configure a battery system User guide configuring a battery system with SmartLink MX
- Troubleshooting Tim Riester TR-LS2 Troubleshooting charge control unit TR-LS2 with MG SmartLink MX
¶ Status indication
Table shows the status LED indication states and their meaning.
| Status LED | Description |
|---|---|
| LED is Off System is off, SmartLink MX is not powered |
|
 |
Green short flash Searching for BMSs on the CAN bus network |
|
Green blinking slow Waiting for start command |
|
Green inverted short flash System is pre-charging |
 |
Green always on Running |
 |
Red always on - no beep In Primary bootloader |
 |
Red blinking - no beep In Secondary bootloader |
 |
Green and red flash alternately - beeping (2 times) All connected BMSs are in failsafe |
|
Green and red flash alternately - beeping (7 times) Hardware configuration failure (check BMSs and batteries: number of cells per battery and number of batteries in series should match each other) |
|
Green and red flash alternately - beeping (8 times) E-stop has been activated. A reset is needed to restart the system |
|
Green and red flash alternately - beeping (12 times) System instability problem detected (contact MG Energy Systems) |
¶ SmartLink MX is not able to detect a BMS
The SmartLink MX must be able to detect a BMS (MG Master LV/HV). In case of that the SmartLink MX is not able to do that, the following must be done:
¶ Diagnose
To validate if the SmartLink MX is having this problem, the following need to be checked:
- Status LED of the SmartLink MX is showing a short green flash: around 25% of the time on, 75% off.
- The MG Diagnostic Tool or MG Connect App is not showing any information about any BMS.
¶ Cause
This problem can have multiple causes:
- Searching for BMS on the CAN bus is not finished yet.
- CAN bus hardware issues.
- Wrong settings of the connected BMSs.
¶ Solution
In some situations, it can be that the SmartLink MX needs a bit more time to detect all the devices on the CAN bus. This should take no longer than 1 minute.
If the problem persists after that time period, double check the following:
- Are the CAN bus wires between the BMSs and SmartLink MX connected correctly? it should be connected to:
BMS (MG Master LV/HV): Aux. CAN
SmartLink MX: CAN-A - Are 2 terminators connected to the ends of the CAN bus?
- Is the BMS configured correctly? Please check Configure a battery system. If yes, it restarted after changing the settings?
- The BMS must be turned on (LED of BMS is continuously on) or it must be in standby mode (LED of BMS is blinking: 50% of the time on, 50% off.).
If the issue is still not solved, a restart of the SmartLink MX might help. This can be done by giving it a power cycle or holding the start/stop button for more than 5 seconds until the status led is going to blink rapidly.
¶ Combined BMS does not start due to voltage difference
In combined systems, BMSs (MG Master LV/HV) need to work together as parallel or redundant system. That is why combined BMSs always are electrically connected to each other by the main DC-bus. This means that they also share the same battery voltage.
Most of the time those battery voltages are the same and starting such a system with SmartLink MX works just fine.
But it can sometimes be difficult to start a system if the battery voltage is not the same.
BMSs will only close their contactor when they are in a safe voltage window of 0.6% of the system voltage for 10 seconds.
¶ Diagnose
To validate if the system is indeed having this problem, the following need to be checked:
- One or multiple BMSs won't join the Combined system anymore.
- The indication LED of the BMS is 75% of the time on 25% off, while the LED of the other BMS is continuously on.
- In the Diagnostic tool or Connect App, the system voltage of that BMS is not the same as the rest.
- In the Diagnostic Tool connected to the SmartLink MX, the combine icon of this BMS is orange:
While the icon of the other BMS is green:
¶ Cause
This issue can be caused in several ways, but the most common is starting a system with some of the BMSs (not all at the same time) and charge/discharge for a while.
Another way is that one BMS opens its contactor (manually or by failure) while the system was fully operational. The voltage difference is then caused by that the other BMS is still charging/discharging. Note that this can only happen if the total active BMSs is still above the required number of BMSs. If the disconnected BMSs is then restarted, it cannot join the bus because of the voltage difference.
¶ Solution
The best way to let the BMS join the system again, depends on some settings of the SmartLink MX.
In all of those solutions, the goal is to get the voltage of both operating and not operating BMSs close enough together by charging or discharging so that it can close its contactor safely.
It’s always recommended to lower the charge/discharge current. This gives the BMSs a bit more time to join the DC-bus. This can be done by adjusting the
current limits. Charging a system is preferred as it can sometimes be more difficult to control a load. Once all the BMSs are operating, the current can be increased again.
It’s always recommended to set the
control modesetting of the SmartLink MX toStart BMS with lowest voltage firstif a charger is available.
When a load is available, this can be set toStart BMS with highest voltage first.
If the combined system is already running while changing this setting, it is needed to restart the system(only the connected BMSs).
-
Number of fully operational BMSs is higher or the same than the
required number of BMSs
If there are more BMSs fully operational than the minimum required number of BMSs, the system is able to charge or discharge. Make sure that the BMS with the lowest voltage is connected to the DC-bus if the system is able to charge and if discharging is preferred, the BMS with the highest voltage should be connected to the DC-bus first. -
Number of fully operational BMSs is lower than the
required number of BMSs
Systems with a lower number of fully operational BMSs can be difficult to start. This is because the system is not allowed to charge or discharge since not all required number of BMSs are operational yet.
At that moment, the SmartLink MX allows 10% of the maximum charge current. The BMS with the lowest voltage can then be charged with a reduced charging current.
Thecontrol modesetting of the SmartLink MX must be set toStart BMS with lowest voltage firstin this case. Restart the system if the setting has been changed.