question

Daniel Suchý avatar image
Daniel Suchý asked

Multiplus 2 - charging - really noisy buzzing

Hi,

I installed my 3x Multiplus 5VA 3 phase system. It's running in UPS mode, currently without any load, it's charging batteries (6x Pylontech US3000C) with current 10A per MP. Firmware updated to latest version (updated yesterday). Everything seems to works very well except one thing. It's really noisy, especially first unit, but other twos are nearly same loud and doing strange noises less often.


Here is video where you can hear strange sounds and buzzing of MP unit: https://photos.app.goo.gl/mjA2cfGGekTSWE9ZA


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Multiplus-II
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4 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Just to rule out the possibility, please confirm you have set this system up as a 3-phase system using VEBus System Config. If not, the three units may be fighting each other when attempting to charge the batteries. Their AC outputs would also not be synchronized when inverting.

You are charging at about 500 watts per unit so part of the noise you are hearing is probably the fan in the Multis.

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Daniel Suchý avatar image Daniel Suchý commented ·
Yea, they are properly configured to 3-phase. I tried to run just one unit (that on video) configured as single phase and noise was same. I tried same for other units and they are little bit more quiet but not so much. I even tried use different input phase, when it was single phase, for that one unit that is most noisy with same result.
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Daniel Suchý avatar image Daniel Suchý Daniel Suchý commented ·
Using VE.Bus for sure, connected and verified in CerboGX. No errors or something.
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rds3000 avatar image rds3000 commented ·

I unaccepted this answer because it's not 'nothing to worry about'.

I just got mine up and running single-phase, and it's super loud....unacceptably so...charging 625 Ah of LiFePo4 batteries at 90A. I've read about the firmware fix v483 from a year ago (10/2021) in https://community.victronenergy.com/questions/104858/excessive-noise-while-charging-via-new-multiplus-i.html, and also some comments there that some units were not resolved with the fix, and were likely a 'bad batch.' My unit is still a freight train after updating to the current firmware.

I bought my unit on Amazon, so perhaps it was from someone trying to offload one of these faulty units? I did get it from the Victron Energy Store on Amazon though. My next move is to try to get warrantee coverage from Victron.

This cannot be 'just the way it is' or Victron would never sell these units. I cannot live with this level of noise, that's for sure. I'm all in with Victron on my install, so I hope I can report soon that this was resolved.

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Daniel Suchý avatar image
Daniel Suchý answered ·

Ok, I did some investigation. That one unit from video is really louder than other during charging, even during absorption it's noticeable noiser. Also I can confirm that noise is not from fan, because I tried to connect load after batteries was fully charged and when fan kicks in it's a noise is really different. Also inverting is much much much more silent that charging for that unit even for bigger loads.


So my question is, is this OK that one unit making these strange loud sounds during charge? Everything works perfectelly, except you can hear it charging two floors up is our house.

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elvis avatar image
elvis answered ·

Is the firmware up to date?

There was a firmware fix for loud noise in the Multiplus II

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Daniel Suchý avatar image Daniel Suchý commented ·

Yea, it is.

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Rob Duthie avatar image
Rob Duthie answered ·

Yes they do maken noises as there is very large toroid transformer in there, depending on the loads etc that have switch mode PSU etc or anothing with DC type motors or even the ripple relay signals will make it hum. My own multiplus 2 can be louder than that at times.

Nothing to worry about.

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Daniel Suchý avatar image Daniel Suchý commented ·
Thanks, at least I won't plan to use charger often, it should be charged via MPPT in future, but I was afraid it's somehow faulty.
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