Same noise, thank you for posting this. It’s not associated to the ball bearings of the fan because I tried sticking a small piece of paper into the fan to jam it temporarily. It still made the noise when the fan doesn’t rotate.
Hi @Jindo , we recommand you switch to mute mode, which will be better for noise reduction. Thank you 
Could you enlighten us where this “mute” mode is so it can be accessed?
I created an account just to say how unusable the machine is while active. I don’t think it is the fan noise because on silent or normal, there is some kind of buzzing noise coming from the machine. It drove me crazy, and i couldn’t leave it in the same room as i am. even with the heavy discount, I find little use for this device if it will have such unbearable noise
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fyi - Silent mode is not referenced in the user guide at all. The only way I was able to set it was to download the Bluetti app, connect to my eb3 and then set Working Mode to Silent
I recall reading somewhere that you can set it using just the buttons on the unit itself. I’ll try and find the instructions.
Edit: I guess I was just dreaming and you do actually need the app. From the manual: " Note: EB3A supports Standard(268W)/Turbo/Silent charging modes. Turbo/Silent mode can be enabled on BLUETTI App."
Sadly, changing to Silent mode in the app doesn’t change that charging noise, which adds 10dB+ to my office throughout the day and makes this unusable as an EPS/UPS in my case where I’m recording audio.
I ended up following another forum member’s hack and added a bigger, but quieter fan on the left intake side which runs every 3 out of 10 minutes via an interval/cycle timer which has helped to significantly reduce the unit’s use of its internal fan. The only downside with this is that the AC cycler timer emits an audible click whenever its relay turns on and off.
Yes, I received mine just today, and indeed it does sound strange.
Hi. I’m going to replace the fan also. Can you please tell me the size of the original fan ? Or if possible the full specs of the original fan (or the model of the original fan).
Thank you.
Does the original fan have just two wires? Maybe what’s needed instead is a PWM fan. At least that might explain the weird noise.
That’s the original fan, it has 2 wires.
I ended up 3d printing my own fan enclosure and using a 5V USB 60mm Noctua Fan. I didn’t want to void my warranty so I’m using it outside of the case.
Yes, I just got a new EB3A unit today (Aug 19, 2023) and the fan makes a significant buzzing sound when the fan starts up for about 30 seconds until the fan spins up to full speed.
The biggest problem with this is for anyone who works around servers or other electronic equipment it sounds like a device with a fan that is blocked or going bad, it’s a real problem if you have it in UPS mode because any time the fan spins up in your equipment closet (in my case just a closet with my home network gear) it sounds like something is broken. Fan noise is fine, broken sounding buzz not so much.
My guess based on the behavior is there’s a current ramp to the fan that isn’t quite high enough to start it spinning cleanly without the long buzz. It needs an initial higher current to start it cleanly (startup noise should be short if at all) then the current to the fan can drop to keep it spinning.
Not sure if this is something that could be addressed in firmware?
I also received a brand new EB3A unit this week (Aug 27, 2023) and first time charging the buzzing started,
it also buzzes annoying loud when nothing is plugged in and is sitting at 100% charge.
I purchased this unit (like many people I presume) for camping but this annoying buzzing/vibrating is unacceptable
I contacted customer support with a video showing the buzzing and they responded claiming tech support said this was normal!
Wait what? Seriously?
The company is ok with releasing a product they know has a design flaw and I guess shrug it off as no biggie!
Looks like this thread is over a year old so not holding out for any firmware update
- the only input from Bluetti Admin here in this thread was to suggest putting in ‘Mute mode’?
Obviously they meant Silent mode but yeah that doesn’t work either as its buzzing when nothing is plugged in.
I agree. The buzzing is caused by the fan power circuit on the board and not the fan itself. I experienced the same thing with one of the first EB3as out and have seen no movement towards fixing the issue or acknowledging there is one.
Just got my EB3A and same noise. They can easily fix this with a firmware and slightly modify the fan speed vs Temp…or use a better quality fan that is compatible with the controller. It don’t bother me much but as soon as the warranty finish I’m going to rip off this fan and replace it with a Betty one.