1000–3000 VA · 120VAC · Online Double-Conversion Lithium Rack UPS
P91 Li lithium online rack UPS
The P91 Li is a 2U online double-conversion UPS built on lithium iron phosphate (LiFePO₄) batteries for rack-based infrastructure that needs continuous conditioned power and predictable lifecycle performance. Online topology delivers zero transfer time and full isolation from upstream disturbances, while LiFePO₄ chemistry adds long service life, reduced maintenance, faster recharge, and stable operation up to 50 °C. Rack, tower, or wall mountable and TAA-compliant, it is designed for standardized deployment across distributed IT, network, and AV sites — including a new short-depth 1000 VA model for shallow racks.
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Overview
Rack-level power protection
The P91 Li is deployed in distributed infrastructure where localized UPS protection is required at the rack level. Online double-conversion topology provides zero transfer time and continuous conditioned power, isolating connected equipment from upstream disturbances. Lithium battery architecture supports longer service intervals, improved thermal performance, and reduced maintenance compared to VRLA UPS systems.
LiFePO₄ technology delivers up to 15 years of battery life — up to four times longer than lead-acid — eliminating routine replacement cycles, while internal runtimes run up to five times longer than comparable lead-acid systems and recharge to 90% in about 1.5 hours.
Key features
What the P91 Li delivers

Where the P91 Li fits
The standard lithium rack platform
The P91 Li operates as the standard lithium rack UPS within the Xtreme Power architecture — deployed in network closets, IT racks, AV systems, and multi-site environments where a consistent platform is required. It sits between compact lithium platforms such as the J60C and high-density platforms such as the J90, balancing flexibility, runtime, and standard rack deployment.

P91 Li vs high-density lithium
P91 Li or J90?
The P91 Li is the standard 2U platform — built for internal-battery ride-through with flexible rack, tower, or wall installation. The J90 delivers the same online lithium protection in a 1U chassis (half the rack height) and adds individual outlet control, plus external battery pack support on its 2kVA and 3kVA models for runtime well beyond what internal batteries alone provide. Choose the J90 when rack space is at a premium, outlet-level switching is required, or runtime must extend past the P91 Li’s internal-only configuration; choose the P91 Li when a standard 2U platform with internal runtime is the better fit.
Model selection
Four models, 1000–3000 VA

All models are 2U (3.4 in) high and 17.2 in wide; depth grows with capacity (the 1000 VA model is short-depth at 10.6 in). Rack depth is measured front bracket to unit panel; add 1 in for the front bezel. Output voltage is selectable (100 / 110 / 115 / 120 / 127 VAC); derate capacity to 80% at 100 VAC.
Battery runtimes
Internal battery runtime by load



