How Much Noise Does a Victron MultiPlus Actually Make?

Steps

1. 1

   Step 1: Introducing the noise test and baseline measurements

   Viewers often ask me how much noise my battery setup makes and whether the hum is annoying. I use a mobile app as a decibel meter to let you hear the actual sound level. Because I live in a house with a wife, kids, and daily household activities, I try to keep other noises as low as possible.

   I also edit the video without normalizing the audio so the volume differences remain clearly audible. At the start of the test in a quiet condition, my app measures around 38 decibels while the Victron setup draws 7 kilowatts from the grid and 447 watts from the battery.

   What I used

   Item	Amount	Notes
   decibel meter mobile app	1	Used to measure sound levels

2. 2

   Step 2: Comparing MultiPlus noise to household appliances

   To give a comparison, online sources state that 40 decibels is the soft hum of a refrigerator or a quiet office. My setup sits just slightly above that right now. An indoor air conditioner unit, specifically the Unity wall unit, runs at about 45 decibels.

   This is roughly comparable to the noise the MultiPlus makes at this moment. When I bring the camera close, you can hear the fans located at the bottom running at a very quiet speed even over the hum.

3. 3

   Step 3: Measuring noise during high power usage

   When I demand a huge amount of power, taking 2.7 kilowatts from the grid and 6 kilowatts from the battery, the MultiPlus units produce about 46 decibels of sound. This volume is comparable to a quiet street. When I ease off the gas slightly and pull 3 kilowatts from the battery, they still produce about 45 decibels of sound.

   When the MultiPlus sends 3 kilowatts back out to the grid, this is the loudest I have ever heard it except when the main fan kicks on.

4. 4

   Step 4: Comparing system noise to indoor background noise

   I walk through the house to let you hear what the average background sound sounds like alongside the MultiPlus. For privacy reasons, I leave the camera in place rather than showing my whole house. Normal household background living sounds, not even counting playing children or the television, easily reach up to nearly 60 decibels in the house.

   When the MultiPlus units are working hard and pumping power back to the grid, they sit at about 45 to 50 decibels. Because I did not have the decibel meter with me during this walk, I plan to place two video clips side by side later with and without the fan.

5. 5

   Step 5: Reviewing the auxiliary cooling and planning the next steps

   For extra cooling, I have additional cooling fans installed underneath the MultiPluses that run continuously at a low speed to maintain airflow through the cabinet. The air coming out of the enclosure is only 25 to 30 degrees Celsius, so the housing does not get hot. For my next step, I want to open up the MultiPluses, remove the covers, and attach temperature sensors to both the mosfets and the coil plates.

   I want to measure continuously for a few days to see how hot the coils and mosfets get and when the main fan switches on, because the main fan creates the annoying extra noise while the coil sound stays practically the same. I believe that with the help of the silent internal fans underneath, the main fan might not even be necessary, meaning I could disable it in the firmware, set it to turn on only at a much higher temperature, or disconnect it entirely and let the bottom fans handle all the cooling.

   What I used

   Item	Amount	Notes
   temperature sensors	multiple	To be attached to mosfets and coil plates
   extra cooling fans	multiple	Installed underneath the MultiPluses for continuous airflow

6. 6

   Step 6: Takeaways

   • The Victron MultiPlus makes about 45 to 50 decibels of noise under load, which is comparable to an indoor air conditioner.

   • Normal indoor background noise in a house can reach up to nearly 60 decibels.

   • Extra cooling fans installed underneath the units provide continuous airflow and keep the enclosure around 25 to 30 degrees Celsius.

   • The main fan creates the most annoying noise while the coil sound stays nearly the same.

   • The main fan turns on preventatively during maximum power charging regardless of temperature.

   • Next steps involve attaching temperature sensors to mosfets and coils to test running the system with the main fan disabled.