Cycling between AC & battery & other strange behavior

BillP · ‎2021-06-29

UPS: APC Back-UPS RS 800VA (BR800)

O/S: Windows 7 Ultimate (64-bit)

S/W: PowerChute Personal Edition 3.0.2

The last few months my UPS has sometimes randomly switch to battery for a few seconds. This happens several times a week. One time my UPS alarm went off and wouldn't stop. The error message said the battery was failing. A manual test I ran then failed. All other tests after that passed. It is possible the battery needs to be replaced but this may be another problem not related to the switching back and forth between battery and AC.

I have been keeping my computer on 24/7 lately. I have set the power setting in Windows to put the computer to sleep after 2 hours. A clue to me was that other devices would not work right sometimes after my computer was brought out of sleep. Also sometimes after my computer was in sleep mode pressing the power button would not start it. I had to power the UPS off and on again before I could power on the PC again. This made think that maybe the USB on my computer was what was causing all the devices even my UPS to have problems.

I made the following change in my power settings for my PC:

Control Panel

Hardware and Sound

Power Options

Advanced settings

USB settings

USB selective suspend setting [Disabled]

It has been several days now. I have had absolutely NO problems with my UPS or any other device after coming out of sleep mode. Does this make sense to anyone?

BillP · ‎2021-06-29

Thanks for replying. I have seen some of this information before.

I am wondering if anyone has had problems like I had and found that it was caused by sleep mode. I want to make sure it is that rather than a problem with my UPS. In any event I will find out in the next few weeks. If I have no more problems then that will prove that sleep mode was the cause of the UPS's erratic behavior.

I am still not sure about my battery. It only supplied power for 4-5 minutes after a power failure a week ago. It used to last at least 15 or 20 minutes. I am going to try a deliberate loss of power and see if that is still true. If it is I will have to consider getting another battery in a few months.

See Answer In Context

BillP · ‎2021-06-29

Hi,

Yes. I found this MS forum post that discusses your issue.

What does "USB selective suspend" mean? - Microsoft Community

I also found this in-depth MS blog

Demystifying USB Selective Suspend - Microsoft Windows USB Core Team Blog - Site Home - MSDN Blogs

Hope this information helps.

BillP · ‎2021-06-29

Thanks for replying. I have seen some of this information before.

I am wondering if anyone has had problems like I had and found that it was caused by sleep mode. I want to make sure it is that rather than a problem with my UPS. In any event I will find out in the next few weeks. If I have no more problems then that will prove that sleep mode was the cause of the UPS's erratic behavior.

I am still not sure about my battery. It only supplied power for 4-5 minutes after a power failure a week ago. It used to last at least 15 or 20 minutes. I am going to try a deliberate loss of power and see if that is still true. If it is I will have to consider getting another battery in a few months.