Can using the wrong CAN bus cable (type-A instead of type-B or vice versa) cause damage to either the Quattro inverter or Pylontech LiFePO4 batteries? Other than the batteries not being recognised by the Cerbo, what else could happen? Aside from best practice, any technical information would be really useful. Thanks!
Not directly due to the wrong cable …
There is no communication with the GX and the charging and discharging functions are no longer monitored by a battery monitor. So if the charging voltage is too high due to incorrectly set Mppt voltages … in the best case scenario, the internal BMS will switch off … but without error messages … because no communication can take place.
a Use without BMS Communication and DVCC Funktionis not recommended anyway.
Like Steffen already said. The lack of proper communication can become a problem. I’ve seen people charge to 60V due to a voltage drop on a cold sunny day. Massive power coming from the panels. BMS thought that there was still headroom to charge the batteries, but that actually wasn’t the case. Customer received a high voltage alarm notification on his phone. Turned out that one of his dogs chew on a cable. Expensive mistake. Be careful!
So in that instance, if the batteries are full, the Cerbo could show them at 80%. But could it work the other way around? If the batteries were at 80% full, could the Cerbo show 99%?
The Cerbo can’t ‘display’ anything here … only when the battery monitor is set to multi does it get any false and not really usable data.
The battery could do something else … I strongly advise against it.
If you have a cable, you only need to ‘change’ the wires accordingly
1 Like
So wind turbine is connected but should disengage before the batteries get full. Middle of the night and batteries hit 100%. Power keeps flowing, taking out four batteries and a Quattro. Any chance this could be due to the wrong CAN bus cable?
How is the wind turbine monitored and what kind of Pylontech batteries do you use? ?
The wind turbine should definitely be disconnected before reaching SOC 100% …
Do you have a Victron SmartShunt installed? I use that to check the charge voltage and current.
Here’s the thing, Sometimes the BMS reports a lower voltage than the SmartShunt. I myself recently ran into an issue where a JK-BMS reported a voltage difference of 0.8V and if I had charged the batteries al the way up to 3.65V per cell, then I would have overcharged the cells to 3.7V. Without me even knowing it.
Edit: Sorry. I somehow got mixed up with another case with a wind turbine. I removed the first part since that was irrelevant to you post.
Our Proven WT2500 wind turbine is DC coupled to the BESS via ECM2501-03 control box. The solar PV is AC coupled to the BESS (5 x Pylontech US5000) via a Solis S6-GR1P6K 6000W Inverter. There is a bidirectional AC coupled Victron Quattro 48/10000/140-2x100 inverter/charger. Settings for the ECM2501-03 PCB were as follows, and were likely not updated by the installer when we went from lead acid to LiFePO4.
| Setting | Description | LED Colour | LED | On (V) | Off (V) | Average Cell Voltage On (V) |
|---|---|---|---|---|---|---|
| FP | Charge Off | Green | D1 | 59.5 | 56.4 | 3.97 |
| TC | Trickle | Green | D2 | 59.4 | 56.1 | 3.96 |
| D1 | Heat 1 | Red | D3 | 57.2 | 53.8 | 3.81 |
| LV | Low Battery | Yellow | D4 | 44 | 48.3 | 2.93 |
| D2 | Heat 2 | Red | D5 | 56.9 | 53.4 | 3.79 |
| D3 | Heat 3 | Red | D6 | 58.2 | 54.8 | 3.88 |
| D4 | Heat 4 | Red | D7 | 58.8 | 55.0 | 3.92 |
| D5 | Heat 5 | Red | D8 | 59.2 | 55.8 | 3.95 |
As part of the upgrade, the operation of one of the contactors was moved from the wind turbine controller to an output from the Victron system. The intention of this was to give the Victron system the ability to open the main contactor and disconnect the wind turbine completely while leaving control of activating “Trickle Charge” mode to the wind turbine controller. The Victron system was configured to disconnect this contactor when the Pylontech battery reported SOC exceeded 98%. However, the contactors were still connected according to the controller manufacturer’s documentation (“Full Power” contactor in parallel with the “Trickle Charge” contactor and heater). In order to isolate the wind turbine, the Quattro would have to open the “Full Power” contactor and the Wind turbine controller would have to open the “Trickle Charge” contactor. The installer also disconnected the AC dump loads.
The open load voltage of the wind turbine control unit was measured on a typical day on the output of the 3 phase bridge rectifier at 127Vdc.
The installer is suggesting that the fault (which occurred at around 2am so no PV) occurred because a type-B CAN bus cable was installed rather than a type-A. Is this even remotely possible?