BN1080G Problems

[Joshie_apc]

This was originally posted on APC forums on 7/31/2020

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Hello, I recently acquired a Back-UPS NS 1080 from someone recently, and I found out yesterday it wasn't working as intended during a power outage.
Before the power outage, to my recent knowledge, the status display was showing the battery as fully charged. I only had three things connected to the battery backup outlets: a laptop charger (not sure of the load), a monitor (~28 W load), and a printer/scanner (not sure of the load). I don't think these 3 sources are over the UPS's rated capacity of 650 W.

When the power went out, all the devices connected turned off, and the UPS emitted the continuous tone. I checked the display and it displayed the F01 error. I went to check the manual to see what this all meant and it pointed to an overload as the problem. There's no way I can overload this UPS with those 3 devices I mentioned earlier. After I got passed the 'fault indicator' screen, the UPS was displaying the battery as close to empty! I doubt the battery could be empty already with this load on it. I started doing some troubleshooting myself. I plugged in the printer/scanner and the continuous tone came on again, signalling an overload. It doesn't make sense. There's no indication that there is a battery error or anything.

I decided to leave the UPS to charge overnight without any load on it. This morning, the display indicated the battery was at full charge. I wanted to test the battery, so I unplugged the UPS from the wall. The battery quickly dissipated its charge from full to close to empty, without any loads on it, in about 10 seconds. There may have been a sound but I can't remember. There has to be something very wrong here.

[BillP]

This reply was originally posted by Bill on APC forums on 7/31/2020

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Hi,

It may be the batteries need to be replaced. let the batteries charge to 100% and then test them with a volt meter. A good 12volt battery should read around 13.6 volts. If they read good reinstall the batteries and switch the UPS to run off battery power. If the charge drops as before, power off the UPS, remove the batteries and check with a volt meter again. If they read low they should be replaced.

[Joshie_apc · Accepted solution]

This was originally posted on APC forums on 8/2/2020

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Thank you so much for responding. 

I wasn't entirely sure if I measured it correctly, but this battery is one of the double 12 V batteries, and I measured 23.9 V. When I let the UPS run on its battery, it did the dissipate fast like before and I read about 43.2 V (I guess RMS) at two of the outlets. After the dissipation, I checked the battery again and it went to 23.1 V.

So, it definitely seems like it can be a battery issue. Thanks for the help.