Different SOC on different pylontechs?

[Marow]

I have five pylontechs.
1x US3000C and 4x US2000C.

But something is strange. The Voltage is all the same, but the SOC (Coulomb) is different.
Why is that?

Bat 4 has 24% and others have around 60% with the same Voltage?
Is there something wrong with my batteries or with the monitoring?

Also, why is the main SOC also just 24%?
If i count all SOC and slice them by 5 pylontechs, i am around 51,8% SOC, not 24%?

Or did i something wrong?
I have the monitoring at console, on the main pylontech US3000C, and than Link to each others.

[RaoulSargent]

Not sure if this will help at all...

I have 5x Pylontechs (4x US3000C + 1x US2000C), and also notice that the US2000C does behave differently compared to the US3000C which tend to all act very similarly - often the US2000C will have a much higher SOC as you describe.
However all 5x batteries seem to be working and delivering their capacity just fine.

This is a 24 hour plot for yesterday (19th Nov 2024):

Although a bit small you can see that the US2000C (the 5th battery) does behave differently, tending to reach 11% SOC about an hour later than the US3000C batteries.
(I have the inverter set to use down to 10% SOC, then at 8% to force charge.)

This is how they look at the time of this post:

[RaoulSargent]

NOTE: I am NOT an expert regards Pylontech batteries... this is only my understanding and experience to date...

In the past when I have had what I thought were issues with my batteries and have contacted Pylontech for assistance, they have always said to make sure that all batteries are on the SAME firmware.

I have no idea of the consequences but Pylontech have also always told me that I should have the US3000C before US2000C in any daisy-chain, with the newest hardware revision being the first in the chain (still all US3000C before US2000C), the first US3000C in the chain should have the newest hardware revision and the highest firmware, and that being the master.

You do have to note however that there are a couple of revisions of the internal hardware of the batteries, and these hardware revisions require the appropriate firmware 'family' for that hardware revision, so the firmware version number may not be the same if you have different hardware versions even if the same battery model.

WARNING: If you load the wrong firmware, a version not intended for the internal hardware revision, it will put the battery into a state where it will not boot and you need to do a manual recovery to get the correct firmware loaded back again.

[Marow]

How to update the firmware? Did they send you a video or something?

[RaoulSargent]

I would start by sending an email to service@pylontech.com.cn and asking if there is anything you should do.
(they have always been incredibly helpful, which is a key reason I am sticking with pylontech batteries).

In the email make sure to provide the current serial number / internal hardware version / firmware version for all your batteries and describe the order in which they are connected (both pos/neg power connections and also the console chain).

[Marow]

Where did i see my firmware? Is it possible with the monitoring?

[RaoulSargent]

If you run an "info" command for each battery you should get an output like this which tells you what you need for each battery.

Device address : 1
Manufacturer : Pylon
Device name : US3000C
Board version : V10R04
Main Soft version : B68.5.0.0
Soft version : V2.8
Boot version : V2.0
Comm version : V2.0
Release Date : 22-09-02
Barcode : PPTC_hidden_

Specification : 48V/74AH
Cell Number : 15
Max Dischg Curr : -90000mA
Max Charge Curr : 90000mA
EPONPort rate : 1200
Console Port rate : 115200

[Marow]

Thanks! I will write them.

But it is and remains strange that the monitoring only shows 24%, although the SOC should be 51% across all of them?

[RaoulSargent]

Based on my own past experience of something similar and how different the SOC values are in your picture ... my hunch (and it is only a hunch) is that you have the batteries physically connected in a chain that does not follow the pylontech advice (US3C before US2C, highest firmware first, same firmware).

Also check that the power connections for +ve start at one end of the battery chain, whilst the -ve start at the opposite end of the battery chain (not both starting at the same battery).

I got a much more even balance across my batteries once I sorted out the cabling as per above.

If you do change the cable ordering then pylontech also told me to always do a force charge and leave all the batteries sitting at 100% SOC for 8 hours to allow them to balance themselves.

As for the SOC values, as mentioned, my 4x US3000C all tend to be in-step with each other whilst my single US2000C tends to report a higher SOC but ultimately all 5 batteries reach 10% about the same time.

My batteries right now are showing SOC: 60%, 63%, 62%, 62%, 69% ... (316 / 5 = Average 63.2%) whilst my inverter is reporting SOC 62% ... close enough but not totally correct.

[Marow]

I have US3000C as the first, there is the monitoring also in.
And than one by one the US2000C.

The + is on the US3000C and the - is on the last US2000C in the row.
But i think the pylontech isnt balancing, cause the Voltage is all the same on every bat... only the SOC is so different