question

mattias-lithammer avatar image
mattias-lithammer asked

Low battery waring on one of three multiplus-II

Hello

What can cause one of thee multipluss-II to show a low battery volt varning (L1). They are cobbected in a thee phase ESS system.

All are connected to same batterypack and SOC is 96% 52,9Vdc. Voltage att dc terminals on Multipluss-II whre 52,8 with the FLUKE multimeter.

All DC connections are checked and re-torqued.

Everything seems to work as intended tho.

skarmklipp.jpg

Multiplus-IIESSlow battery warning
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7 Answers
marekp avatar image
marekp answered ·

@Mattias Lithammer

You could measure voltage drop on each component in the DC connection between the battery and MP.

It could be increased voltage drop on the fuse in L1 channel.

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mattias-lithammer avatar image
mattias-lithammer answered ·

Hello have measure the voltage drop on DC during about 2000W Ac load and it was 0,030Vdc on all MPs. That is about the highes AC load i will experience at the time.

Is there a setting somewhere? th warning starts under 53 Vdc.

The battery pack is protected by a external BMS.

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hardy-tuner avatar image
hardy-tuner answered ·

Yes. You can set DC input alarm in „VE configure 3“ on third tab „inverter“

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mattias-lithammer avatar image
mattias-lithammer answered ·

The values in DC input alarm was way lower than 53 so that was not the problem.

Any other sugestions?

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mattias-lithammer avatar image
mattias-lithammer answered ·

After scanning this forum for like the third time for this issu i think i found the solution.

Dynamic cut-off and restart offset in the ESS settings. This is only for phase 1 you send these settings. So I've changed them a bit to see if the low battery warning changes.

Please correct me if i am wrong.


an.jpg



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nuxland avatar image
nuxland answered ·

I had the same, my cut off was 47v and offset 1,2v and when voltage went under 48,2 it gave me L1 low voltage warning. It happened when I tested to go as low as 5% of soc :).

So it seems yeah, that as you could only configure this "voltage cut off" on ESS assistant only in First inverter then this error goes out also only in L1 and is confusing if you do not know what is causing it.

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hipik634 avatar image
hipik634 answered ·

I had the same issue. Might have been the cut off, I changed it anyway. But in my case it was about grid - on the second folder there is a switch that is supposed to block feed in. I have had a safety switch assistant put on the same aux port which then disabled feed in and blocked inverter somehow. There should be warning about assigning already assigned input there ...

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