Do inverters etc, wear out?

[Anonymous user]

I've got a SUA1500RM2U that recieved new batteries in 2009. The UPS reports 23 minutes of runtime at 35% load. According to APC's specs the unit should reach 45 minutes of runtime at that load. I don't remember what runtime was being reported when the batteries were replaced but 3 years (and only about 4 major power events) later and runtime is horrible, is this normal?

We're seeing this same scenario play out in other UPS units, some that were stocked with APC batteries and others with compatible parts. So the brand of battery is a factor but so is the age of the UPS, since they're all right around 10 years old. My question is, do inverters etc. wear out over time? Should we be replacing entire UPSes??

[BillP]

Batteries generally last 3 to 5 years. The inverters themselves do wear out over time as does anything else however that would not affect the runtime as it's not necessarily related(inverter and run time). We usually consider 10 years the lifetime of a smart ups so I would suggest trading up to a new UPS. This doesn't necessarily mean the UPS will not last longer but as the UPS and it components age, they are more likely to fail.

[Anonymous user · Accepted solution]

UPS's integrate three systems: a rectifier, one or more batteries and an inverter for each phase served. Electrolytic capacitors in both, rectifiers and inverters have been reported for many years to dry out, thereby losing their capacity and increasing their internal resistance. This in turn accelerates self heating and an ever increasing speed of the wear-out mechanism. Memory, which holds the firmware, and interconnects are also particularly sensitive to absolute temperature and temperature cycling, producing additional stresses on electronics, which can cause premature power electronics failure. These can be quite catastrophic if the power stage blows up during cascading events that did not lead to a controlled, rapid shutdown within microseconds. Batteries, based on their electro-chemical storage mechanism, fail slower, but are even more sensitive to temperature, discharge rates and charge/discharge cycles. Hence traditional fuel gauging is insufficient to determine state of charge, let alone state-of-health. At infiniRel we have developed a technology to determine capacitor wear-out non-invasively, while the unit is operating. We intend to further develop the technology to include battery health and I'd encourage you to send us your feedback via the above website.