Vertiv Liebert PSI5 Lithium Ion UPS - 1500VA 1350W 120V Line Interactive AVR 2U Rack/Tower, 0.9 Power Factor, Sine Wave, 3 Programmable Outlets, Rotating LCD Display, 5 Year Warranty(PSI5-1500RT120LI)

Picked this up to slip under the entertainment setup, which also has a server system in the case. The rack mount version works great for this, fitting into what used to be a VCR/DVD wide slot to support an old TV. After reading the reviews, I was expecting to need to install their software to do battery state detection for the system, or get an SNMP card for it, but it was auto-recognized by even old MacOS versions. It is silent except while charging or running on battery, and even then the fans don't ramp up much unless you push it towards the maximum load. I've been impressed by the extended run time this provides, especially compared to my old APC BackUPS 1500 with an additional external battery pack. This is more efficient, lasts longer on a charge, doesn't have as much overhead when keeping watts low, and thanks to the lithium tech, it should last virtually forever since it'll be in reasonable temperatures and not used extremely often. I just wish I could set it to only charge to 90% and not discharge fully either to make the lifespan of the battery even longer. Awesome and well thought out unit. Easy to pull the battery for a swap, which is a fairly standard LiFePo pack so replacements won't be a problem in the future, and I love the rotatable display feature. It is just a small attention to detail that makes everything else shine. So far I love it, though I've yet to install the software management for it on Linux to try and tweak with any further settings. I generally have good power, so this doesn't need to do any conditioning and kicking in for that, so while I see other reviews mention it has a wider allowable power range, I don't have a way to test that, nor am I worried about it.Cons: There is really only 1, but I'll mention 3 for people considering the rack mount/tower one vs the mini tower. The first is the only real con...the fan is weird and pulses up and then down, every short bit, while charging. Reading the firmware updates, this MAY be fixed with an update, but I haven't done that yet. The second is that I wish it showed watts for output, rather than amps. This is a simple calculation, but I find watts more helpful to see when talking about system power draw and the like. The last is just something people need to be aware of. This thing is LONG compared to the mini tower. I measured and it fits for me, but make sure you do too if you're not putting it in a standard size server rack mount location. It would work well as a monitor stand...the old style CRT big bulky ones...but would take up way too much space to put on top of a desk. In the tower mode though, it is quite thin thanks to the standard rack mount sizing, so you could stand it up under/behind a desk quite easily. It comes with both rails for mounting in a rack and some feet for using it as a standing tower. The bonus con is that while the non-lithium series has external battery packs to add capacity, this doesn't...but for any reasonably normal use you won't have a capacity issue with this, and you could get a higher output capable version to pick up more capacity in the process if you really needed it and were set on these.TLDR: Would definitely buy again at this point if I needed another, so long as the price is reasonable at that time.

As a long-standing user of APC products, I recently explored alternative solutions due to a series of quality control concerns with APC. The Liebert PSI5 caught my attention for its promising features. Despite its higher price point compared to our usual purchases, the inclusion of lithium-ion batteries suggested potential savings through reduced battery replacements and a possible extended UPS lifespan. Additionally, its lighter weight facilitated an effortless installation, particularly for rack setups.However, the rack rails supplied with the PSI5 appeared less robust than those from APC, with poor tolerances that necessitated additional time to align screws properly. The removable plastic front panel also presented challenges in fitting, requiring excessive force that raised concerns over potential damage.Upon initial use, the unit did not respond to the standard procedure of turning on, which involves holding the power button for two seconds. Despite attempts with various button combinations and connecting a small load, the unit failed to operate until it unexpectedly powered on after several minutes. This initial experience raised doubts about the unit's reliability.The Power Assist software, which accompanies the Liebert PSI5 UPS, features a user-friendly setup for configuring email alerts and shutdown parameters, but necessitates the installation of .Net Core. This detail aside, the software falls short in offering the depth of features found in APC's PowerChute, notably missing the capability to adjust power thresholds for managing line fluctuations. This limitation became apparent with the PSI5 issuing unwarranted power failure notifications in our server room, despite its consistently stable power supply—a challenge not faced with other UPS brands.The software's limitations extend to its logging capabilities. While the event log offers scant details beyond a generic "No AC detected" message, the data log's shortcomings are more pronounced during these false positive events, displaying only null values instead of useful data. Moreover, the redundancy of log entries exacerbates these issues, with up to 64 duplicate entries recorded for a single incident. Such redundancy not only clutters the log but complicates the task of diagnosing and managing power conditions effectively.To circumvent the disruption caused by these unnecessary false alarms, I found it necessary to disable email notifications for brief power outages, setting a minimum duration before an alert is sent. This workaround, while effective in reducing interruptions, underscores the need for more sophisticated diagnostics and management tools within UPS software, allowing for a more nuanced approach to power condition monitoring and response.Unlike other reviews I didn't notice any fan noise issues, but the unit is located in a cold server room with relatively noisy racks and HVAC.UPDATE: I was having some line noise issues so I put an EMI meter on the Liebert's electrical outlets. The readings were 5 times more noise than an APC UPS running on the same circuit. This is probably okay for a computer but definitely a problem for audio/video equipment.

I've got this UPS installed in my rack, and so far it is working well. I was expecting to be able to just hook it up via USB to my linux box and monitor it using NUT (Network UPS Tools)... However, this UPS is not supported by NUT. Argh...In case you were curious, it uses a removable 48v 5Ah/240Wh LiFePO battery pack. Large, but not that large: my $150 "solar generator" (which can be used like a UPS in a pinch) has a capacity of 333Wh...This is a AVR UPS, so even though it is a lithium-ion system (The chemistry is LiFePO if you are curious) it will still be heavy. The AVR features work, but allow the voltage to swing pretty wildly (at least +/-15v) before changing the windings on the transformer to compensate. My older AVR UPS had much finer-grained control (keeping the voltages within +/- 10v).Don't let the "PSI5" name and that expansion port in the back fool you, this device cannot be set up with a runtime extension battery pack (not that it was ever advertised as supporting it). I fell for this line of thinking, even though I thought I had adequately researched it beforehand (read the wrong datasheet). Turns out that none of the li-ion versions of the PSI5 series support external packs (which makes sense, but I was holding out hope anyway). When you remove the expansion connector cover, you will see that there is no connector inside.My UPS was shipped to me with the battery connected, which seemed odd... But everything works. It arrived with a ~60% charge.Was it really worth the extra cost? Maybe. I'm still a little bitter about it not being supported by network UPS tools (NUT), but maybe that will change.