But the main point in the article is worthy: UPS manufacturers have been skimping somewhat on functionality, features and quality over the past few years...
I still have a few APC Smart UPS's bought in 1999-2000 running in my house; at the same time I had a few cheapies that broke after a few years, sometimes in spectacular ways (electronic exploded melting part of the battery case); I will not name brands, it is not worth.
Since 2000 I changed cases full of batteries, usually every 2-3 years. The good thing with the APC Smart series is that it works even if it gives an alert that the battery is bad, but you will get a few minutes of power instead of 30-60 minutes (my server & NAS is very low power, 5% of the UPS capacity). I also set the server to shutdown when the battery is reaching 50%, so I never deplete the batteries. At the same time, the UPS on the water pump is usually running on batteries as much as it can, so I need to change these batteries after 2 years. I have both the server and the water pump in the basement, the temperature is around 16-20 degrees Celsius (winter-summer), when I was keeping the server and the UPS in the house the battery life was at half (~18 months). The heat and the deep discharge cycles are effectively killing batteries.
I had the same type of battery on my motorcycles, one lived about 8 years and a second one 6 years, but in very different conditions: it was warmer, but almost no discharges.
I've used UPSes that discharge batteries no lower than 10.5 (no deep discharge) and only once in a couple of years and that charge them to and keep them at 13.6 volts under stable room temperature all year. All batteries lost most of the capacity after 3 years, two almost all of it, one had like 40% left. In five years only that one was still surviving short minutes outages, while initially was able to do a few hours. For comparison, I had one battery just laying around for 6 years in the same room without touching it and it lost only like 30%.
I found this forum posting while searching for how to maximize the runtime on my APC UPS: https://forums.overclockers.com.au/threads/hacking-the-newer...