3

I am using Ubuntu and I have an APC Back-UPS 550 uninterruptible power supply that's worked pretty well for several years.

However, over the last year, it's "bad battery" alarm has routinely started activating, and each time appears to be a false alarm.

A loud persistent piezo buzzer blares while it's status LED flashes between green and red. According to the manual, this means the lead-acid battery is bad and needs to be replaced. However, upon inspecting it, he battery has a full charge and is in perfect condition.

Just to be safe, I bought a new battery, and the problem went away, but then about 6 months later, the bad battery alarm came on again. I know these batteries don't last forever, but they should last for 3-4 years, not just 6 months.

What's causing this, and is there any way to fix it? Is the UPS unit defective? Is there any way I can disassemble it and either fix or deactivate this "alarm". Since the unit otherwise works great, I half suspect this is just APC's way of trying to get me to buy more batteries, which aren't cheap.

Edit: Discovering some docs on APC's website, it says the false alarm buzzer issue can sometimes happen if you overload the unit and connect too many high-wattage appliances to it, even when it's on external power. I can't be sure, but that might have been my problem. The unit seems designed to power a typical desktop pc and maybe a monitor, but I was using it to power two 1U servers, a desktop PC, and a hefty wifi router.

I'll try redistributing some of the load to a second ups and see if that resolves the problem.

1
  • Its possible the UPS itself is faulty too. On our company, this would be a time where we would replace the UPS altogether. If the UPS protects servers that can't go off, you do not want to have a wonky UPS behind it that may fail spectacually somewhere in the next months taking the server with it.
    – LPChip
    Dec 4, 2021 at 14:19

2 Answers 2

4

Download the APC UPS Daemon command line tool and use it to disabled the APC Back-UPS 550 alarm.

Note: This advice is based on software that was last updated in 2016 and I recommended in another answer back in 2020. I know I have successfully used it on macOS back in the “OS X” days in the past but haven’t in years. So hopefully this will work for you.


This only works if you have a data cable that can connect to the APC UPS’s data port from your PC. But if you can, you are in luck! And if you somehow can’t, the alarm is typically just a piezo buzzer connected to the UPS mainboard by a modular 2-3 wire connector. Meaning open up your UPS, find that connector and just literally disconnect it. But software disabling is honestly better since it is not invasive and easy to reverse.

That said, there is a cool command line tool called the APC UPS Daemon that can allow you to control an APC UPS from the command line easily without having to install the official PowerChute GUI software. It’s available for Mac and Windows as precompiled binaries as well as RPMs and Deb packages for Linux in addition to pure source code that you can compile an pretty much any system.

This blog post from 2012 does a decent job of explaining specifically how to use the APC UPS Daemon software to disable alarms. Here is the command line flow once you get the APC UPS Daemon software software installed and apctest is available:

sudo apctest
 
2012-11-18 23:30:50 apctest 3.14.8 (16 January 2010) debian
 Checking configuration ...
 Attached to driver: usb
 sharenet.type = DISABLE
 cable.type = USB_CABLE
 
You are using a USB cable type, so I'm entering USB test mode
 mode.type = USB_UPS
 Setting up the port ...
 Hello, this is the apcupsd Cable Test program.
 This part of apctest is for testing USB UPSes.
 
Getting UPS capabilities...SUCCESS
 
Please select the function you want to perform.
 
1) Test kill UPS power
 2) Perform self-test
 3) Read last self-test result
 4) View/Change battery date
 5) View manufacturing date
 6) View/Change alarm behavior
 7) View/Change sensitivity
 8) View/Change low transfer voltage
 9) View/Change high transfer voltage
 10) Perform battery calibration
 11) Test alarm
 12) View/Change self-test interval
 Q) Quit
 
Select function number: 6
 
Current alarm setting: ENABLED
 Press...
 E to Enable alarms
 D to Disable alarms
 Q to Quit with no changes
 Your choice: Select function: d
 
New alarm setting: DISABLED
 
1) Test kill UPS power
 2) Perform self-test
 3) Read last self-test result
 4) View/Change battery date
 5) View manufacturing date
 6) View/Change alarm behavior
 7) View/Change sensitivity
 8) View/Change low transfer voltage
 9) View/Change high transfer voltage
 10) Perform battery calibration
 11) Test alarm
 12) View/Change self-test interval
 Q) Quit
 
Select function number: 6
 
Current alarm setting: DISABLED
 Press...
 E to Enable alarms
 D to Disable alarms
 Q to Quit with no changes
 Your choice: Select function: q
 
1) Test kill UPS power
 2) Perform self-test
 3) Read last self-test result
 4) View/Change battery date
 5) View manufacturing date
 6) View/Change alarm behavior
 7) View/Change sensitivity
 8) View/Change low transfer voltage
 9) View/Change high transfer voltage
 10) Perform battery calibration
 11) Test alarm
 12) View/Change self-test interval
 Q) Quit
 
Select function number: q
 
2012-11-18 23:32:59 End apctest.

Note that if you get an error like this when running sudo apctest:

apctest FATAL ERROR in apctest.c at line 313
Unable to create UPS lock file.
  If apcupsd or apctest is already running,
  please stop it and run this program again.
apctest error termination completed

It means that the apcupsd (APC UPS daemon) is active and running. You need to stop the apcupsd process to run apctest. How to do that depends on what OS — and what method you used — to install it.

On a Linux system simply running sudo service apcupsd stop or outright killing the process with the PID via a command like kill -TERM [PID] should be enough to stop the process.

More extensive details on usage and debugging of apctest can be found here at the University of Waterloo’s Wiki page on acupsd or in this blog post.

4
  • I can't get apctest to work, and it looks like the project is dead and unmaintained. It hasn't had any new development or releases since 2016. With the ups running and connected to my computer via USB, running sudo apctest just gets me: apctest FATAL ERROR in apctest.c at line 313 Unable to create UPS lock file. If apcupsd or apctest is already running, please stop it and run this program again. apctest error termination completed.
    – Cerin
    Dec 4, 2021 at 14:31
  • @Cerin Sorry to hear this. FWIW, It seems that if the APC UPS Daemon (aka: apcupsd) is running you cannot run apctest. As the error states, “If apcupsd or apctest is already running, please stop it and run this program again.” Look at this blog post here as well as this other forum post here. If you cannot start apctest you need to stop apcupsd before running apctest. Dec 4, 2021 at 17:00
  • PS: And more extensive details here at the University of Waterloo’s Wiki page on acupsd. Dec 4, 2021 at 17:05
  • 1
    Yeah, even if I stop the daemon, I still get an error. Running apcaccess status reports "COMMLOST" so it looks like either apcupsd doesn't support my device or the USB port on the device itself no longer works. However, running lsusb does show the ups when connected.
    – Cerin
    Dec 4, 2021 at 19:15
1

I am not sure about the answers above - but what I did was to use the PowerChute software - attach a data cable to the 550 backups and connect to your computer, then use the APC software to turn off all notifications, then apply.

It worked for me and is simple. But yes, it does mean, no alarms at all (which is what I wanted as I only use this particular backups in a power cut and the annoying beep every 2 minutes was driving me mad): APC has even produced a simple video for it.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .