Battery going offline when min SOC reached

Q&A and troubleshooting
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1

Hi,

Hoping someone has seen this before (or maybe its a feature in new versions)

I recently did updates on all components of my system:

  • Victron 5kw inverter

  • 3 x pylontech batteries

  • Gx device

After the update I noticed that now when my system reaches min soc it shows 1 battery is offline:

Screenshot_20260702_204802_VRM
Screenshot_20260702_204802_VRM3120×1440 261 KB

If I change min soc to be a bit higher then all 3 batteries show online and it charges to min soc then 1 goes offline.

In the morning when sun is shining and its charging all is fine and 3 batteries are online until the end of the day when I reach min soc again.

I looked at the batteries and when it reaches min soc and a battery goes offline then there is a red light on my master battery.

No alarms on my system in VRM.

Anybody seen this behavior?

2

How are your batteries connected (power wise)?

3

Yes. Seen it
They do that when they are unhappy.

The reason is one unit is blocking charge or discharge. In your case discharge. Its probably reaching a loww threshold before the others
Try rotation in the bank and see if that helps.

4

Ah thanks!

So a bit more info - I have 2 x US3000C and 1 x US2000

Could the US2000 be the issue since it’s smaller and running out of capacity sooner?

The US3000C is my master battery and it is the 1 that has the red light on when min soc is reached (I set it to 30% recently… maybe I must increase it)

5

Do you think keeping the bank at 100% for a few days to balance it out might help?

6

IMG-20260630-WA0083
IMG-20260630-WA00831920×3413 742 KB

Does this answer your question @DuivertNL ? Its been working fine like this for a few years.

7

Looks ok, what battery is the newest?

8

Is the 2000 a newer or older one?
I would have it in the middle of the stack.

Its possible a good charge is all it needs. How often does it get to full?

9

The 2000 is the oldest battery. What is the benefit of having it in the middle? (Asking to learn) :slight_smile:

I have set my system to keep batteries charged so will leave it for a few days at full charge to see if it helps.

It was getting to full charge daily but for the last 2 months my solar wasn’t working 100% (blown fuse) so it didn’t. That has been fixed 2 weeks back.

10

The way the stack will current share. The battery in the middle will work less than the outer ones.

11

Ok that makes sense - thanks for that. Will arrange to have that done.

Changed ESS setting to keep batteries charged so will leave it like this for 2 days then test again.