I used the EB3A as a UPS (Uninterruptible Power Supply) for my Ender 7 3D printer, as well as a Raspberry Pi to control it using Kipper. Today, there was a power outage, and the circuit breaker tripped.
Upon reaching the 3D printer downstairs, I detected a burning smell, initially attributing it to the 3D printer itself. However, it wasn’t caused by the printer but by the EB3A UPS. As I attempted to disconnect the 3D printer from the UPS, I noticed smoke emanating from it.
It turned out that instead of safeguarding me from power failures, the EB3A caused the power failure. Fortunately, my circuit breaker activated, preventing further damage.
I would be interested to see an expert’s analysis of the failure with an explanation if these units have enough safety built in or not. Generally, I expect devices like this to shut down when any unsafe conditions arise, like overloads or high input voltage and I know these units have quite some of these safeguards built-in. Maybe this one has a production fault or there was an external condition like a power surge. Did any other of your devices fail?
If your unit is under warranty you should contact your seller or Bluetti directly for repair or replacement. You cannot get it investigated by a third party in that case. But at least it would allow Bluetti to learn about the failure condition, whatever it was.
Based on my experience, early EB3A have some issue being used as actual UPS. I had 5 of them back in March and had to return 4 due to the overload error. My last one that doesn’t overload overheats in UPS mode (powering 20W of networking equipement) and I have to tape a USB powered fan on it to make it work. Once I’ve done that, it has been running solid for 7 months straight.
Are you running 200W continuously 24/7? Or at 200W peak?
While the EB3A is technically a pass-through where the input grid power is directly connected to the output, I wonder how much power it draws. On my 20W setup in UPS mode, it still gets hot, hot enough for to overheat unless I tape my own USB fan on it. For some reason, the built in fan doesn’t spin in UPS mode, only when it is charging or using the inverter