question

sesshoumaru avatar image
sesshoumaru asked

Order of things: Adding a US2000C

Hi

I know this is no Pylontech Forum, but please bear with mef or a moment.
I have 8 Pylontech US2000C modules in a rack. I now have installed a second rack and installed additonal 4x US2000C (4x to come end of the year). Both battery racks are independently connected to the busbar. I used a default flat network cable to bring the 2nd linkport of battery 8 to the 1st linkport of battery 9 in the second rack.


However, upon putting the second rack under power, switching from off to on on the 4 new batteries, hitting the red SW button on the master battery (battery 1 in rack 1) ... nothing happend.


So I am asking myself... how is the correct order of doing things?? Somebody already did what I am trying to do? Help would be appreciated.


Thanks :)

cerbo gxPylontechQuattro-II
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2 Answers
Duivert NL avatar image
Duivert NL answered ·

always connected the newest battery as master, then link to additional new batterys and then to older one's

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sesshoumaru avatar image sesshoumaru commented ·

I cannot just rebuild everythig (well, can but reluctant).

The system is operational and feeds the house. Its probably not a good idea to disconnect the battery pack to move batteries.


All batteries are US2000C .. so why change the master? Newer firmware should be able to deal with that (both racks / battery towers) are 5m apart behind concreate walls. So no easy cabellig changes :/

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nickdb avatar image nickdb ♦♦ sesshoumaru commented ·
This shouldn't be done online. Shut the system off, and as per the manual, wire the new batteries as master. They likely have newer firmware and so won't appreciate older ones as master.

Make sure all the LEDS all show the same SOC, this is also in the manual iirc, they document it properly.

Then power the master followed by the rest.

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sesshoumaru avatar image sesshoumaru nickdb ♦♦ commented ·

Is it possible to extend the CAN-Bus Cable, which goes into the current master, with a normal ethernet cable to have it going to the "new master"? Its about 10m up and down. I could then use the existig cable to bridge back to the rack1, effectively making rack2 the master - not that I mind.


I just mind shutting off the system. Runs without hitch since 2 years.
I can check the SOC ... but I have no charger anyhow, so the batteries have just to cope.

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nickdb avatar image nickdb ♦♦ sesshoumaru commented ·
You may need to just make one of your own to the right length. Extending these types of cables isn't a great idea, you really don't want to risk comm errors.

The pinouts for A/B cables are easy and published, you just need the right crimping gear, or know someone who does.

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dognose avatar image dognose sesshoumaru commented ·

You can extend it with a regular ethernet cable, not another bms cable.


As for errors: don't buy the cheapest rj45 connector (female-to-female) you can find and you should be good.

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Duivert NL avatar image Duivert NL sesshoumaru commented ·
maybe im wrong but from your posts it looks like you have add the new one's without shutting down the system?
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sesshoumaru avatar image sesshoumaru Duivert NL commented ·
Yes, and they probably behaved gracefully in doing nothing.

I probably have to move the two battery towers, switching positons. For which I most probably have to shut down the inverters. Really.. there should be a mode for that, passthrough, where the battery is not touched and the normal AC power can "smoothly" still flow from AC-in to AC-out....

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nickdb avatar image nickdb ♦♦ sesshoumaru commented ·
The inverters are not designed to operate without a battery, this isn't a secret. There are larger considerations when making major changes to the DC bus of an inverter system. If you're off grid there should be a changeover switch to power the home from generator while you do maintenance.



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Duivert NL avatar image Duivert NL sesshoumaru commented ·
We’ll thats why it’s not working you can not do that online…

Follow the manuals and tips from what nickdb allready posted

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d4h-ottmar avatar image
d4h-ottmar answered ·

i'm at least with nickdb and way more to check.

Here my list: check firmware of every stackmember of the battery. PT have at least two different hardware versions named C. Also check the new delivered batteries. What makes you sure, that they are not rest in stock for a while? At least double check your configuration and start your system as PT and Victron recommend.

Otherwise what you guys do, is try and error with a high risk to damage parts of the system.

For such situations i always deploy a Bypass switch (grid connectivity)!

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sesshoumaru avatar image sesshoumaru commented ·
I have a bypass switch, I just had the hope that battery upgrade, where you just daisy chain some batteries on the end does not need all of that ;)
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