I received a new EB3A this week and have set it up in UPS mode, plugged in to AC with a computer (~40-60W) connected to the AC output.
I’ve noticed periodic buzzing every 10-15 minutes or so, which sometimes (but not always) is followed by the fan coming on.
I read similar reports of this both here and on reddit but it they seemed to be older. Is this still a normal issue with these units or are some ok? I like the features of the EB3A but may return it to Amazon due to the noise.
Here’s a video of the noise. It sounds quieter than it is in the video, but towards the end the noise stops and you can hear the difference.
Hi @sean, Generally, when the machine’s charging or discharging power reaches a certain level, the fan will start. The fan will also start when the internal temperature of the machine reaches a certain threshold, and it will shut off once the temperature decreases, which may cause periodic noise.
We suggest setting the charging mode to Silent Mode in the Bluetti app and observing whether the buzzing sound persists. If the buzzing disappears, it may be due to the fan starting because of high load or high temperature.
It seems there might be background noise from the video in the environment. We recommend testing the machine in a quiet, open space while simultaneously charging and discharging. If the machine noise is still loud, we advise contacting customer service for a repair.
Thanks for the reply, I am already working with customer service on this.
For reference, the silent mode makes no difference here (I had already tried that). The buzzing happens regardless. The video is taken in a quiet room with no other noise so all the noise is from the unit. At the end of the video you can hear it go completely silent once the buzzing stops.
I did see suggestions elsewhere to use an external fan blowing into the air vent to help keep the unit cooler so I am trying this at the moment. So far with an external fan I have not noticed the buzzing or the internal fan coming on.
My feedback to Bluetti is to enable an option to keep the internal fan on while plugged in to external power to help keep the device cooler. This could be a firmware update. Otherwise a better cooling system in future hardware designs.
Hi @sean, Thank you for letting us know.
I think our customer service team will help you resolve this problem.
And I have forwarded your feedback to our R&D department. That is very precious advice.
The fan buzz on the EB3A has been a known issue for a long time, as you’ve seen from other posts. The EB3A also has known issues with overheating and failure to deliver the full rated amp output via the 12v cigarette plug. If you still can I’d return it and look for something more reliable.