Back-UPS XS 1300LCD - Time left under load decreases when devices are unplugged

[BillP]

A recent ice storm knocked a good chunk of my city off the power grid.  I wanted to try and keep power to my cordless phone as long as possible, so I tried to maximize my UPS battery by unplugging all of the other devices connected to the UPS.  When I did this, I saw my 'time left' drop from something like 300 minutes to 200, and it kept on going lower and lower as I was unplugging devices which were drawing power.  I found this strange, and began plugging things back in, and saw the counter go back up to 300 minutes.  Why was this happening?  I assumed I would have more power after unplugging devices.

[BillP]

It was definitely not wattage, but the time remaining.  I checked the wattage screen at the time, my usage dropped from 6 watts to 2 watts after I had everything else besides my phone unplugged.

[BillP]

I asked around (and even have a BX1300LCD myself at home) and have never seen this type of issue. Does it still continue if you do any testing or has the problem gone away? My first thought based on some feedback here is to reboot the UPS and observe (just as you'd maybe reboot a computer) if there was something strange going on.

To reboot this UPS if you'd like to, you can turn off and remove any attached equipment (and if you have the USB cable connected, remove that). Then, turn off and unplug the UPS from AC power. Disconnect the battery and hold down the power button for 15-20 seconds and then reconnect the battery and plug the UPS back in. You can then turn it back on and perhaps reconnect your equipment or do further testing maybe to see if behavior has changed.

[BillP · Accepted solution]

Did you verify that the display on the screen was showing minutes left/remaining (versus wattage the UPS was providing)? That is what comes to mind first - I've never seen that before.