I had a MultiPlus-II 48/8000/110-100 installed about a week ago. Recently, when the solar yield increased and the unit began charging the batteries at roughly 5,000W, the internal fan became excessively loud.
I measured the noise level at 66 dB. For context, this occurred on March 27th with an ambient garage temperature of approximately 20°C.
This noise is disruptive enough that it can be heard clearly inside the living areas of the house. Given that the weather is currently quite cool, I am highly concerned about how loud the unit will get during the hot summer months. If it is this loud now, the noise will inevitably disrupt our sleep during warm summer nights.
Since this unit is designed for indoor installation, the lack of noise levels (dB ratings) in the official datasheet is a significant oversight. Discovering this level of noise only after the installation is complete is incredibly frustrating; had this been clearly documented, I would have reconsidered this model or changed the installation placement.
I have two questions:
Is a 66 dB noise level under a 5,000W load at 20°C ambient considered normal for this specific model?
Are there any recommended mitigations? (e.g., firmware adjustments, fan retrofits, or acoustic enclosures that do not void the warranty).
Please check the attached video when I captured the noise level and the charging levels at that time as well.
Lots of various ways / ideas to mitigate the noise - early models had a hardware mod of extra fan control circuit board, some have replaced the internal fan / added external fans / mounted unit on noise reduction fixings and many more ideas.
General search should bring up posts for you to decide how to proceed.
Does it lower the noise level? What happens in summer when the temperatures are higher? Isn’t adding more fans increases the noise level? I can see you have the 5000 version, it could be quieter from the start.
Personally i never take what a manufacturer states as gospel, that’s what independent reviews are for.
I knew of the reported noise before i purchased and if i wanted a silent inverter i’d of gone for an SMA, as i already have one and its absolutly silent, but its not as user configurable as victron - so victron it was for me.
I’m afraid you have choices and currently these are do something to mitigate the noise of your current choice or change your inverter.
The dealer didn’t tell me because I didn’t ask. I didn’t ask because I had no clue they get that noisy. My previous experience was with a Fronius PV inverter that’s completely silent and I just assumed that this Victron is silent as well, because nothing about noise is mentioned in their datasheet. It should be specified directly in the main documentation the noise levels, I should not have to ask around about something as important as this.
The stock fans run at full speed or off.
The external ones have intel 4-wire PWM control.
I start at 24C and 100% at 28C.
This prevent the stock fans to be switched one most of the time.
My external fans are Artic P80 PC modding silent fans. Though a different quality.
Up to 1,5kW the or 30% load continuously the internal fans do not start.
I full comply, Victron should have upgraded all their MP2s with silent PWM-controlled fan from stock.
