Reduce noise of fanned charger

My charger is a aluminium box with a fan inside.
Its makes sort of a hollow windy sound.
Its not that the sound it particularly loud but since the fan runs 6 hours to charge a battery fully it gets annoying.

So how do you people reduce the noise of a fanned charger?

I have not heard the fan alone without the box but im guessing that the fan is not making much noise alone.
I think the noise is when the air blows inside the aluminium box.

My charger is not waterproof.
But i could mount it outside when charging. Then take it inside when done.
That way the batteries are inside in the warmth and the charger/noise is outside.
Maybe if my charger was waterproof that would be a good solution.
Dont know if this will be a good idea for my charger in case it rains or high moisture or below freezing.

Charger pictures: https://scootergrisen.org/forum/viewtopic.php?f=3&t=3601

Replace with a Noctua fan

1. Decrease fan speed
2. Change aerodynamically unsuitable input/output to better design
3. Revise air flow inside charger
4. Noctua fan

Some pictures and/or link could be helpfull

Replace with a Meanwell. Then you have both waterproof and fanless.

Other than the Cycle Satiator from Grin Tech http://ebikes.ca, then the last solution, Meanwell HLG-xxxH-xxA series LED PSU is the most certain way to remove the noise completely. they're potted and sealed, so can be mounted to the scooter or bike as well, and plugged in anywhere (will work on 115 or 230v ac input, autoswitching). I use both the Satiator and the HLG-600H-54A for charging the SB Cruiser trike.


If you just want to reduce the noise as much as possible with your existing fan and charger, then remove the grilles at both ends of the charger. This reduces turbulence which decreases noise, and increases airflow.

This usually requires removing the endcap plates, removing the fan from the one it's on, then cutting out the areas of the endcaps with the airholes. Make sure you leave the mounting holes for the fan.

You can further shape the area at the fan's contact point to smooth and shape it to match the fan's ring area, which will reduce turbulence (and noise) a little more, but not very much and it's a lot of work.

Flipping the fan around so it pulls air thru instead of pushing it in may also reduce the noise, if it's not already setup that way. Buut...you should mount the fan on the other end of the charger if you do this, so it still flows air in the direction it was designed to.

The fan itself will still make noise, and the smaller the fan is for moving the same amount of air, the more noise it will make (because it has to spin faster and makes more turbulence).

You can change to a less noisy fan of the same size, that still moves the same amount of air (CFM).

Or if you don't intend to carry the charger around, and don't care how big it is, you can build a box-reducer-duct and use a much larger fan at a lower RPM to get the same CFM, for less noise. This means making a box that is much larger at one end to hold the new fan, and small enough on the other end to fit against the opening in the charger. Again, pulling air rather than pushing it will usually be quieter.

Something I've done with chargers that will get mistreated and exposed is to build a wooden box and secure the charger in it. Then I mount 2 larger diameter more quiet fans (for redundancy in case one fails), one at each end of the box (one blowing in and one blowing out). Be sure to orient the charger so the cooling air flow inside is the same direction as the flow of the new fans to enhance the cooling flow inside. The resulting cooling air flow over the charger keeps it running cooler and the wooden box muffles much of the whiny sound of the charger's internal fan. Dampening material reduces noise even further.

I've yet to have one of these modded chargers fail and several of them have been in daily use for over 8 years. With stock chargers I've seen failures from small insects getting inside and even the eggs of tiny lizards, so as added protection I install screen over both ends to keep creatures, hair and most of any dust and water out. Despite that significant reduction in flow the charger still runs cooler than stock.

For those rely on their ebike for transportation, have only 1 charger, and live where a new charger is over a week away this kind of extra effort necessary to help prevent being dead in the water.

take your charger apart and try to change how fan is mounted
I had similar problem.
I used plastic screws and rubber gaskets to mount fan , this silenced fan quite a bit.
the problem is noise resonates throughout enclosure.

Turns out a roll of toilet paper with toilet paper still on it works pretty good when put tight against where the fan is.

I saw a video with something called a duct silencer.
It sort of looks like a big toilet papir roll with insulation on the inside.