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cocodanila asked

Excessive noise while charging via new Multiplus-II 48/5000/70

Hello community,

I am running a 3xMultiplus II 48/5000/70 configuration, monophase, all 3 in parallel, all on latest version 508 but the issue was also in 506 etc. I am running dynamic ESS, but was manifesting in simple ESS as well

Symptoms are similar as in this post https://community.victronenergy.com/questions/139719/multiplus-ii-quattro-ii-noise-vs-original-multiplu.html?childToView=141060#comment-141060.

What I have notice it is happening mostly in the morning when solar power is in the area of 3-4 times the load and equal with my setting of pushing into the grid (2-3KW of power). Out of the blue (but some how in sync with sudden change in output or in solar power) even enough power in the battery to feed the grid and the load, the inverter start pulling from the grid and start charging the battery and the load with 2-3KW, and making that horrible noise. The status of invertor is flicking from bulk to passthrough and back and registering a message of overcharge. If you put the system in inverter mode is stabilize back. I've notice sometime, if changing grid setpoint might stop the noise and stabilize the system, but this is not working all the time.

I was wondering if someone else has the same issue?

PS: yes same cable length on input and output, but no change!!


Multiplus-IImultiplus in parallelseplos
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Alexandra avatar image Alexandra ♦ commented ·
What batteries do you have. Do they have DVCC control on the system? How full are they when this is happening?
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cocodanila avatar image cocodanila Alexandra ♦ commented ·

Bateries are 3 Seplos on CAN, with Pylontech in between them. DVCC is active now, with current and charging tension limit with sharing all 3 parameters active.

SOC it does not matter I think, same symptom anywhere in between 30% (my bellow ESS limit to 70-80%)

Today, some more info: all went fine at sunrise up till the PV power was close to double the load. I had to keep it on inverter until PV reach 5 times the load. It struggle for a while (like 2-3 minutes) but went quite at the certain time

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cocodanila avatar image cocodanila Alexandra ♦ commented ·

Today, it happen again ; system started with bypass, PV charging the battery until reach something like 2.5 the load. I guess that this is normal, the inverters are doing some calculations/averages before switching into different mode. Then when reach something like 2.5 times the load for a while (I guess like 5 min), it is starting disconnecting the main (Dynamic ESS is off) and I guess some software bug is happening as is starting charging from the main and the PV in the same time, although there is no need from main. I have a strong vibe that instability of the system would be until 5 times the load and then will stabilize. I will let you know, I have to wait 15 min from disconnecting the main (just started again!!!). Meet you at PV 3.5K!!!

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3 Answers
cocodanila avatar image
cocodanila answered ·

Bateries are 3 Seplos on CAN, with Pylontech in between them. DVCC is active now, with current and charging tension limit with sharing all 3 parameters active.

SOC it does not matter I think, same symptom anywhere in between 30% (my bellow ESS limit to 70-80%)

Today, some more info: all went fine at sunrise up till the PV power was close to double the load. I had to keep it on inverter until PV reach 5 times the load. It struggle for a while (like 2-3 minutes) but went quite at the certain time

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manta avatar image
manta answered ·

You cold login to your Seplos battery and lower down the max charge current for each battery, in the range of something like 70A.
Canbus will communicate this with your Multiplus DVCC settings. This would likely solve the issue. At least you can try.

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cocodanila avatar image
cocodanila answered ·

It is already limited from 200 to 100, and on top DVCC is limiting the overall at 250 (for 3). Control now is in Victron, Seplos is doing only the protection part

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