P91-2kLi vs Vertiv Liebert PSI5-2200RT120LI
Both are 2U, 120V lithium rack/tower UPS around 2 kVA. The Vertiv PSI5-2200RT120LI is line-interactive, rated 1920 VA / 1920 W. The Xtreme Power P91-2kLi is online double-conversion at 2000 VA / 1800 W, with more runtime, a lighter chassis, more outlets, operation to 50 °C, a battery rated for up to 15 years, a 6-year warranty and TAA compliance.
What the P91-2kLi brings
Zero transfer time and continuously regulated output, against line-interactive AVR on the PSI5.
13 minutes at full load and 27 at half load, against Vertiv’s 8.6 and 19.
33.5 lbs against 39.5 lbs, in the same 2U.
Eight 5-15/20R against seven.
Runs in hot closets and edge rooms; the PSI5 is rated to 40 °C.
LiFePO₄ rated for up to 15 years, against 8 to 10 years.
About 1.5 hours to 90% after an outage.
Electronics and lithium battery (USA and Canada), against 5 years. Reduced to 2 years at 40–50 °C; 2 years depot repair elsewhere.
Qualifies for U.S. government, education and public-sector procurement; distributors list the PSI5-2200RT120LI as made in China and not TAA compliant.
P91-2kLi vs PSI5-2200RT120LI
| Feature | Xtreme P91-2kLi | Vertiv PSI5-2200RT120LI |
|---|---|---|
| Topology | Online double-conversion | Line-interactive with AVR |
| Output capacity | 2000 VA / 1800 W | 1920 VA / 1920 W |
| Rack space | 2U | 2U |
| Depth | 19.0 in rack (about 20 in with bezel) | 20.1 in |
| Weight | 33.5 lbs | 39.5 lbs |
| Runtime at full load | 13 min at 1800 W | 8.6 min at 1920 W |
| Runtime at half load | 27 min at 900 W | 19 min at 960 W |
| Recharge | About 1.5 h to 90% | About 2.1 h to 100% |
| Battery | LiFePO₄ (LFP), hot-swappable | Lithium-ion, hot-swappable |
| Battery life rating | Up to 15 years | 8–10 years |
| Operating temperature | 0–50 °C (derated above 40 °C) | 0–40 °C |
| Outlets | 8 × 5-15/20R (one controllable bank) | 6 × 5-20R + 1 × L5-20R (3 programmable) |
| Input cord | 6 ft, 5-20P | 10 ft, L5-20P |
| Network card | Optional Web/SNMP | Optional |
| Warranty | 6-year full (electronics and battery) | 5-year |
| TAA compliant | Yes, standard | No (made in China, per distributor listings) |
Where the PSI5 leads: more watts (1920 W against 1800 W), a locking L5-20R outlet, three individually programmable outlets and a longer 10 ft input cord.
Vertiv and Liebert are trademarks of Vertiv Group Corp., referenced here for factual comparison only. Vertiv figures are from Vertiv’s product page and distributor listings, checked October 2026; verify current specifications before purchase. Runtimes are shown at each unit’s own full and half load (Vertiv 1920 W / 960 W; P91 1800 W / 900 W). Vertiv recharge is to 100%; P91 recharge is to 90%. TAA and country of origin for the Vertiv model are from distributor listings. The P91-2kLi depth is rack-mounting depth.
Compare the P91-2kLi with Eaton, Vertiv and APC →Choosing between them
Choose the P91-2kLi for servers, storage, network gear and generator-backed sites that need online double conversion, for the longest runtime in this class, warm rooms up to 50 °C, the longest battery life and warranty, and TAA procurement. Choose the PSI5-2200RT120LI where line-interactive protection is enough and the extra 120 W or a locking L5-20R outlet matters.
Need more capacity? See the P91-3kLi 3000 VA comparison. Need 1U? See the J90 1U online lithium UPS.
P91-2kLi vs PSI5-2200RT120LI: frequently asked questions
What is the difference between the P91-2kLi and the Vertiv PSI5-2200RT120LI?
Why does online double conversion matter?
How does runtime compare?
How long do the batteries last?
Is either TAA compliant?
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