Whenever the fan kicks on my EB3A makes a really strange 25 second sequence of electrical noises coming from near the intake fan on the left side of the unit. The fan is spinning slowly during this time. After this sequence the fan ramps up considerably to operating speed. Here’s a sound clip of it: SndUp | Post info. Has anyone else noticed or experienced this? Should I be worried?
The unit works just fine otherwise and this only happens when the unit gets warm and needs to active the fan.
I think its normal, mine does the same plus at least one youtuber has noted it as well. A bit irritating but better than most of my other Bluetti power brick fans that run full blast whether charging or not.
I found the review you’re talking about:
Brand New - BLUETTI EB3A - 268wh LiFePO4 Power Station - Full Testing and Review - YouTube. Glad to hear I’m not the only one. Perhaps they can address this is a future firmware update if even possible.
It is an issue on some units. (mine included). The noise is a buzzing / vibrating noise coming from the fan voltage regulating circuit on the board. The nois is NOT coming from the fan itself. I purchases a good quality ($40) ball bearing fan and replaced mine. Same noise, did not change. The fan sound itself is better with my new fan, but the buzzing is still there.
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
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.
