On November 29,2013 I had finally bought a UPS. Previously, my first server (Core2Quad) had been in continuous operation for 4 years, with only two interruptions due to a power failure. However, this was twice too much for me, especially since the Intel „fake“ RAID didn’t want to get into gear again and again. This was especially when I was at school or at work and had to retrieve data for the training.
IT problems always arise when you can use them least.
So server, switch & router to the UPS and go. I hadn’t considered other factors like temperature at that time, because everything was in the attic, so it wasn’t „too cold / too warm“ or also: something between 14°-36°C – is already working….
A year ago, the UPS then migrated to the living area, where I had to switch it more often. In this case, the battery level usually dropped directly to 40% and then ran a little bit. (see measurement results)
So we needed a new battery and we all know where to get RBC123 (please use preferred suppliers here).
APC promises the following values ex works:

This improved the runtime accordingly.
Measurement results:
old battery

new battery

I have to say that I don’t have the UPS on my PC, so I didn’t tell her that she got new batteries.