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bm97ppc asked

PylonTech Force-L2 - 2 x 3 Module Stacks only seeing half the modules

Hi,

OK so I have 2 Stack of 3 PylonTech Batteries modules, Cerbo GX and a Multiplus II.

I have connected the batteries as per manual (Cerbo GX BMS CAN -> Port0 with Type A cable and Port1 to Port0 of second Stack). However It only reports 3 modules and the available capacity of 3 modules (222Ah).

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I have connected to each stack independently and both independently report there 3 modules, implying both the BMS modules are working. However, when connected together they don't seem to want to collectively talk and report 6 Modules.

Unfortunately have no way to verify the firmware of the 2 BMS modules i.e. it is the same or if that even matters. Concerningly the sticker on the 2 BMS are different with a manufacture date 2 months apart so not that bad but they have defiantly changed something in that time. I have email Pylontech to see if there is a way to connect to check the firmware versions but so far, no reply.

Any suggestions / experiences of this?

Regards

Piers


BMS
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6 Answers
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bm97ppc answered ·

OK, finally got to the bottom of this. It was the cable / Link between them,

In the process of trying to diagnose this I tried several cables both made and manufactured cables which made no difference. After working with Pylontech using there diagnostic software, them setting up a Lab in China replicating my setup to confirm no firmware / software issues and swapping units round with a 3rd BMS. it was concluded that it must be the link between the 2 (and the start-up sequence / process is quite critical too)

So focusing on this I tried a Shielded Cat5e between the 2 and that seem to do the trick, there is no recommendation to do this but seemed to help in my case. I have since made up a STP cable with the water ends on and this did not work (I tested the cable and it is 100% including Shield). I am at a bit of a loss to this but I at least know for sure the problem.

As for Start-up process,

  • Disconnect Victron GX device from BMS.
  • Powerup only the batteries (main Double pole breaker)
  • Powerup BMS’s starting with Master (BMS single breaker)
  • Wait 60Seconds
  • Press start button on Master Stack only for 5 Seconds.
  • Wait 60 seconds
  • Connect back up to Victron GX device.


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bm97ppc answered ·

Did your L2 not come with straight-wired cables, mine did?

In my case they would have worked but I cut one end off to feed through some trunking and re-terminated it.

To add to my comments above I did finally get to the actual bottom of this. It was not the Shielded cable that made it work just a coincidence of a manufactured cable and startup sequence.

The real problem was the RJ45 connectors I was using, I have terminated network cables for 25 years, I have the proper testers, and never had a problem. I was testing my cables and they tested 100% perfect. I had even used 2 maybe 3 brands of connectors all failed. Finally, I used an Ideal crimp tool and Ideal crimps and it worked (Ideal is the brand).

It seems the Force L2 is very fussy about the RJ45 connector.



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bm97ppc answered ·
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tkaktins112233 avatar image
tkaktins112233 answered ·

Hey , we have the same problem ,

We have 4stacks with 16modules . And we can't get communication between them . Tried your start up process and no result . Depending on what you said the main thing is that the problem is in cables ?

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tkaktins112233 answered ·

Guy's . .. After long hours we got the answer how to make it work .

In manual there is CAN cable you have to connect in ports . NOT WORKING !

Take category6 ethernet cable or 5e and make it like STANDART ETHERNER CABLE -2M long ! and amazingly it works . Paired 4stacks with 4x modules .

Thank god for this posts author . He made us realize that there is cable problem not software or something else. good luck

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tkaktins112233 answered ·

and follow the steps author mentioned - but for L2 it is ok for 30sec waiting time .

As for Start-up process,

  • Disconnect Victron GX device from BMS.
  • Powerup only the batteries (main Double pole breaker)
  • Powerup BMS’s starting with Master (BMS single breaker)
  • Wait 60Seconds
  • Press start button on Master Stack only for 5 Seconds.
  • Wait 60 seconds
  • Connect back up to Victron GX device.
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