5.0 out of 5 stars Great UPS!

2026-03-06    -Dave

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.

Unit work ok but there are missing parts

2026-01-25    -frederic

The unit is working fine but, I have two problem with that purchase:First, shipping. It was suppose to be "in stock" but still took 10 days before shipping. It looks like the provider they are using has it in stock but not the seller.Second, quality control. There are missing/loose screws and pins. The box looked factory seal so I guess the problem is with the Vertiv quality control.I've look everywhere in the box but could not find the missing parts.

5.0 out of 5 stars Solid backup

2026-02-14    -Ron

ThIs unit is performing as expected. It was worth it to me to pay more for the lithium ion battery. I had two questions about the UPS, both of which were answered promptly by the manufacturer to my satisfaction. The quick responses are also appreciated.

Unit work ok but there are missing parts

2026-02-09    -frederic

The unit is working fine but, I have two problem with that purchase:First, shipping. It was suppose to be "in stock" but still took 10 days before shipping. It looks like the provider they are using has it in stock but not the seller.Second, quality control. There are missing/loose screws and pins. The box looked factory seal so I guess the problem is with the Vertiv quality control.I've look everywhere in the box but could not find the missing parts.

3.0 out of 5 stars Seems to work well, not supported by NUT

2025-12-23    -darco

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.

5.0 out of 5 stars Solid backup

2026-01-13    -Ron

ThIs unit is performing as expected. It was worth it to me to pay more for the lithium ion battery. I had two questions about the UPS, both of which were answered promptly by the manufacturer to my satisfaction. The quick responses are also appreciated.

5.0 out of 5 stars Great UPS!

2026-01-01    -Dave

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.

3.0 out of 5 stars Seems to work well, not supported by NUT

2026-01-02    -darco

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.