Pylontech battery strange thing

Hi, I have 5 Pylontech US3000 batteries connected parallel. But the LEDS on the front show different values.
The system (2 Growatts SPF5000ES) in parallel mode, charging this bank.

No errors at all.

What's the issue here?

At first blush, you seem to have 1 pack at a slightly higher voltage than the rest...
I will GUESS that you have the (+) & (-) coming off at the TOP of the rack busbar and THAT will do it.
Put the (+) at the top and the (-) at the bottom of the bars.
Then ensure that the wires from both are the SAME LENGTH Exactly to the common DC Bus and hen from the common DC Bus to the AIO's.
Exact length of the wires & lugs, Do Not Include shunts, fuses etc in the length.

I won't argue that... Shnieder, Victron, Midnite and other Tier-1 Manufacturers/VARS state the same thing and I believe the Engineers & designers and this has been proven to be SO TRUE in the real world. There is contention on this point which comes from YT Genius Wizbangs parroting twaddle they believe cause they saw it on video...

1 point to consider & understand. Every connection, fuse/breaker/lug etc ADD Resistance & line loss. That MUST be accounted for and corrected/adjusted to compensate.

The voltage readings at BATT Terminal & AIO will show that difference and IT IS DIFFERENT when Charging or just Discharging. Many Tier-1 products have offset setting to correct for such, I do not believe Growatt Basics have that, therefore you have to correct manually. Use at least a 2 Decimal Point Accurate DVOM/DMM and measure the voltage at AIO Terminal & Batt Terminals during charge & again at discharge, note the differences and adjust accordingly.

Thank you. The plus (+) IS at the top and the minus (-) IS at the bottom of the bars. Sorry, you can't see it in this picture.
And the wires are the exact same length and there are no shunts or other fuses or so in between.

How do you charge them independently to be the exact same voltage? Of course I have a DMM. Is is okay to disconnect all of them and then charge them one by one to 100% SOC? And then reconnect them all again?

I'm not familiar with the specific particulars for Pylontech packs themselves.
I think you may be able to just turn off the packs with the switch, no need to unhook it all. Easy way to test, leave the middle pack ON and turn off the rest, if things are still powered, it'll work.

Do you have an App or PC Software to access the pack BMS' ? it might be worthwhile to review settings, cell voltage etc before starting a charge process... there could be other hints about issues.

If connected to the Growatts and interacting with them, the AIO's may also be contributing if the settings don't quite line up. Even simple things like a 0.1V drop between inverters & Packs can have peculiar outcomes. This can be amplified with paralleled inverter systems & paralleled closed loop packs.

You may also have to press the "SW" red button to turn off the BMS

Are all the connections clean and tight?

Have you measured the battery voltages (at rest!) of each on the battery posts?

In parallel mostly promotes similar voltages. I am not sure how the green light (state of charge or voltage?) is determined.