[Nut-upsuser] Random but persistent USB disconnect/reconnect with MGE Pulsar Ellipse Premium

[George Anchev]

Hi,

My UPS is MGE Pulsar Ellipse Premium 1200VA, connected on USB port,
usbhid-ups driver.

Using simply KNotify about UPS connection states I noticed that sometimes
unpredictably a notification appears that the USB connection to the UPS is
lost and a few seconds later another notification appears that the
connection is restored. And this repeats to infinity. The only way to get
out of it is to shutdown the machine, turn off the UPS, unplug the power
and restart everything again. I had no luck finding a pattern when and why
it happens. This has never happened before, only in the last 3-4 months. A
friend said he has noticed similar peculiarity with other MGE UPS units.

The batteries are fairly new (changed late January 2015) and there have
been no power outages since then (maybe one or two for 2-3 minutes only).
However I notice that a short power off test (like the one I just did)
makes the battery fall from 100% to 86% for less than a minute and then
charges very long to reach 100% again.

What could be the problem (and possibly the solution)?

P.S. When connected - everything works fine, shutdown upon power failure,
battery "holds" the computer normally etc.

---
George
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