HI,

Recently I have added a UPS for my Unraid server - APC Back UPS BX950MI.

Below you can check my current settings. All looks fine to me, but as soon as I cut off power to the UPS, Unraid shuts down immediately.

Additionally I got this Alert:

UPS Alert

Emergency! Batteries have failed on UPS FuxlNAS. Change them NOW

I'm grateful for any help.

P.S: Unraid 7.3.2. Internal boot enabled.

diagnostics-20260817-1058.zip

Edited August 17Aug 17 by Fuxl66

You should run a test program on the UPS (on Windows or something) checking the batteries.

Maybe they are really worn out (they do not last forever, 3-5yrs are good for APC build ones to my experience).

Prepare to buy new ones and exchange them, then reload and cut power again to check if they now work.

Another possible reason for the shutoff maybe an overload. UNRAID usually shows you the percentage used on the UPS, make sure you have quite a lot of reserve.

the current load of 13% make me sleep tighter and more calm...

Thanks for your reply.

You can see in my screenshot a load of 12% (62W).

I am going to check the battery, but it´s new

Maybe that ups alert ...

1 hour ago, Fuxl66 said:

Emergency! Batteries have failed on UPS FuxlNAS. Change them NOW

Serious words used. Could be the ups protecting your equipment from it's failed batteries by doing immediate shutdown. I suspect when that alarm clears it will do what you want.

2 hours ago, Fuxl66 said:

Emergency! Batteries have failed on UPS FuxlNAS. Change them NOW

This is likely the issue, if the batteries are being detected as failed, it thinks they cannot run the server without power.

7 hours ago, Fuxl66 said:

I am going to check the battery, but it´s new

Did you reset the battery install date (or whatever your brand of UPS requires) when you replaced the battery.

APC requires doing this, else it retains the status of the previous battery.

I have changed my USP (thanks Amazon).

I have directly connected it to my laptop via USB. System Check successfully.

I connected my Unraid server to the USP (USB + power plug) WITHOUT power connection for the USP.

After the successfull bootup all seemed fine. Status "on battery" runtime left "19 min"

after additional 4 minutes, USP decided to shutdown the system. without any reason. 15min left, but it should run down to 5min as specified.

Any idea? I pretty sure we are able to exclude my UPS as the problem.

A little late to this thread, but just thought I would comment on the settings you have for your UPS.

The purpose of UPS isn't to allow you to run on batteries as long as possible. The purpose of UPS is to allow you to run long enough to get through very brief power outages, and to allow your server to shutdown cleanly if the outage is more than brief.

The parameter you should be setting is Time on battery before shutdown (seconds). 300 seconds or less is my recommendation. You need to figure out how long a clean shutdown actually takes.

You don't want to allow the battery to run down very far. It is not good for the battery, it takes longer to recharge, and you don't want to restart your server on an UPS with depleted battery.

You need to remove the values to disable them. Only use one and preferably the last option starting with 300 seconds.

Right now three simultaneous things could happen:

1. Unraid shuts down at 0% battery which means it could run until the battery hits zero which is no good.

2. The UPS waits until there is 5 minutes left of runtime to shut unraid down which means if your server uses enough wattage to cause the timer to hit 5 minutes it will initiate a shutdown even if there is 99% battery left.

3. Lastly, time on battery = 0 seconds means as soon as a power loss event occurs, it will immediately attempt to call a shutdown.

Edited August 19Aug 19 by MowMdown

13 hours ago, Fuxl66 said:

I pretty sure we are able to exclude my UPS as the problem.

I don't think so, as UPS status change from on battery to shutdown, it should be the reason why UR will shutdown even timeleft sufficient.

Why you setting override power capacity in 520/410 ？Pls try empty those setting.

Edited August 20Aug 20 by Vr2Io

I have removed all settings and just keeped

Time on battery before shutdown (seconds): 300

the log shows

Aug 26 08:58:19 FuxlNAS apcupsd[1548516]: Battery disconnected.

Aug 26 08:58:30 FuxlNAS apcupsd[1548516]: Battery reattached.

Aug 26 08:59:22 FuxlNAS apcupsd[1548516]: Battery disconnected.

Aug 26 08:59:23 FuxlNAS apcupsd[1548516]: Battery reattached.

Aug 26 08:59:42 FuxlNAS apcupsd[1548516]: Battery disconnected.

Aug 26 08:59:43 FuxlNAS apcupsd[1548516]: Battery reattached.

Aug 26 09:01:21 FuxlNAS apcupsd[1548516]: Battery disconnected.

Aug 26 09:01:22 FuxlNAS apcupsd[1548516]: Battery reattached.

Aug 26 09:07:28 FuxlNAS apcupsd[1548516]: Battery disconnected.

Aug 26 09:07:29 FuxlNAS apcupsd[1548516]: Battery reattached.

irregularly this notification comes up.

UPS Alert

Emergency! Batteries have failed on UPS FuxlNAS. Change them NOW

On 8/17/2026 at 1:11 PM, ConnerVT said:

Did you reset the battery install date (or whatever your brand of UPS requires) when you replaced the battery.

APC requires doing this, else it retains the status of the previous battery.

12 minutes ago, ConnerVT said:

  On 8/17/2026 at 7:11 PM, ConnerVT said:

Did you reset the battery install date (or whatever your brand of UPS requires) when you replaced the battery.

Yes I did. Now I am going to test Network UPS Tools (NUT) for UNRAID instead of the integrated apcupsd.

Let´s see if I have the same problems.

On 8/26/2026 at 10:40 AM, Fuxl66 said:

Yes I did. Now I am going to test Network UPS Tools (NUT) for UNRAID instead of the integrated apcupsd.

Let´s see if I have the same problems.

Since my last comment I did not found anything bad in the log.