UPS Going Bad?

Current issue: Have a Cyber Power 825avr ups that’s rated for 450w protection. Current load on the ups is 230w for my main server and nothing else on it. Replaced with a fresh battery. When testing the load (pulling the plug with a load on the UPs) the server is forced to a hard reboot. I can watch the server reboot when the power is switched over to battery but it does come up and the UPs supports the draw.

I am not sure if I am running into an overload situation where the ups is not able to support the draw or if the ups itself has an issue. I only need the ups to help the server perform a graceful shutdown. It should have enough run time to support this.

I am not sure where to start, or if I just need to look for a new UPs.

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Is is the first time you’ve hooked it up to your main server?
What’s the power supply in your server?

I’m asking this question because I’m wondering if your server is equipped with a power supply with APFC and that circuit is having issues with the simulated sine wave out of the power supply. I’ve come across this issue before and the only way around it was to get a pure sine wave UPS.
But now I’m moving way too fast. Those details I asked about might point us to the solution to this problem.

This isn’t the first time it’s been hooked up to it, but I am not sure if it didn’t have this issue from the start. The power supply in it is a Corsair model power supply, I think 650watts. Could it mean I should look for a different power supply?

What does the power / battery setting in the os of the server set to?
Is the server’s power / battery setting being managed by the os or cyberpowers software? Is the usb cable plugged into the battery backup and the server?

I wouldn’t switch PSU because all the modern ones come with APFC and it’s for the better, allows for more efficient conversion from AC to DC.
If you have a bunch of old incandescent bulbs or lamps that combined use around 200W and try to plug the UPS when they’re connected. If it drops out is the UPS, if not there might be incompatibility between them.

I suggested incandescent bulbs because they’re just resistors and it’s the simplest load you can connect to it.

I’ve actually had a similar issue with my APC UPS once I replaced the batteries in it and it’s because the UPS is not aware the batteries were replaced.

You need to connect to the management software of the UPS and actually tell it that you replaced the battery and reset the battery constant by doing a full battery calibration. This will basically tell the UPS that there’s a new battery in and it’ll know how much power it can draw from it.

Look into how to do it on your UPS as APC UPSes you need to bitbang hex values via console as they want APC techs to replace the batteries and reprogram it instead of having a user do it themselves.

This one is a Cyber Power ups that is controlled by nut-server and not plugged individually into (through USB) to the server. Also this same issue happened before I replaced the battery. I thought it might be the battery that was causing this issue but I guess that was wrong.

I’ll look into getting a similar load put on the ups and see if it runs.

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Running a calibration on the UPS and self-tests would be a good start which would require to use the Cyberpower software. The battery % shouldn’t drop at all after 4 or 5 different self-tests.

I am not familiar with Cyberpower UPSes as they’re very rare in EU, but from experience with any kind of UPS, you should always run a calibration test after a replacement.

Although when looking up cyberpower 825avr and it’s manual, it mentions Win95/98/WinXP so it’s very likely it got capacitor plague’d if it was manufactured around 2007

I was able to put a different load on it around 200 watts with my Cisco lab gear. Pulled the plug on the UPs and watched the console output from one of the routers. Nothing rebooted once I pulled the plug this time. That’s about 9 devices in total between switches and routers and an RPi.

Also this model is the 825AVR-G, not quite as old as the 2007 model but it’s not a spring chicken.

2 big issues with ups systems are aging capacitors in the power banks, and the batteries themselves.
Batteries are easily replaced and cause less stress on the charger/ control system if done so in a timely schedule.
Capacitors on the other hand are problematic due to current fluxuations they endure over their useful life.
And due to the construction of the charger and control boards, its difficult to properly test them for shorts and leakage without removing them from the boards.
In general what must be measured is the cost of repair, downtime, and labor compared to the cost of outright replacement.

Many times in industry its far cheaper and faster to just replace it outright.