P91-6K vs APC Smart-UPS SRT6KRMXLT
The Xtreme Power P91-6K and APC Smart-UPS SRT6KRMXLT are both 6 kVA / 6 kW online double-conversion VRLA rack UPS for enterprise servers, network, and telecom infrastructure. Both deliver full 6 kW; the P91-6K differentiates on longer baseline runtime, TAA, and warranty.
What the P91-6K brings
- Longer full-load runtime (5 min vs 2 min 17 sec)
- Expandable runtime with external battery packs
- Flexible rack or tower deployment
- TAA compliance for federal procurement
- 3-year battery coverage (vs 2-year)
Side-by-side specifications
| Specification | Xtreme Power P91-6K | APC Smart-UPS SRT6KRMXLT | Advantage |
|---|---|---|---|
| Capacity | 6 kVA / 6 kW | 6 kVA / 6 kW | Comparable usable power |
| UPS topology | Online double-conversion | Online double-conversion | Equivalent protection |
| Runtime (full load) | 5 min @ 6 kW | 2 min 17 sec @ 6 kW | P91 – longer runtime |
| Battery technology | Sealed lead-acid (VRLA) | Sealed lead-acid (VRLA) | Comparable architecture |
| External battery packs | Yes | Yes | Runtime expansion supported |
| Rack height | 4U (2U UPS + 2U battery) | 4U | Similar rack footprint |
| Form factor | Rack / tower | Rack / tower | Flexible deployment |
| Input / output voltage | 208/220/230/240 V | 208/220/230/240 V | Comparable |
| Warranty | 3-yr UPS / 3-yr battery | 3-yr UPS / 2-yr battery | P91 – longer battery coverage |
| Compliance | UL1778, CE, FCC, RoHS, TAA | UL1778, IEC 62040-2, RoHS | P91 – TAA for federal procurement |
Specifications from Xtreme Power’s supplied P91-6K vs APC SRT6KRMXLT comparison; based on publicly available manufacturer data. The P91-6K runtime reflects the system with a BPXR2U240A battery pack. Both occupy a similar 4U footprint.
Choosing between them
Both deliver full 6 kW online VRLA protection in a similar 4U footprint with external-pack expansion. The P91-6K leads on runtime, warranty, and TAA; the APC fits APC-standardized environments.
Choose the P91-6K if you need
- Longer baseline runtime at full 6 kW load
- TAA compliance for government / regulated procurement
- Flexible rack or tower deployment
- Expandable runtime with external battery packs
The Smart-UPS SRT6KRMXLT may fit if you need
- Standardization on the APC Smart-UPS ecosystem
- Sites aligned to existing APC runtime infrastructure
- Non-TAA commercial deployments
Related comparisons
Specifying a centralized 5-10 kVA online UPS?
Xtreme Power supports UPS selection, runtime sizing, and distributed infrastructure design across IT, networking, AV, and regulated environments.