Your rack or tower needs dependable UPS critical power, but the two APC options in front of you take opposite paths. One is a complete new 3000VA UPS. The other is a used external battery pack that extends runtime on compatible systems. Choosing between them starts with whether you need a full UPS or additional battery capacity for one you already run.
Quick verdict
Choose the APC Smart-UPS XL SUM3000RMXL2U if you want a complete 3000VA 120V rack/tower UPS in new condition. Choose the APC SMX120RMBP2U if you already have a compatible Smart-UPS X unit and want a 2U external battery pack to extend runtime.
Comparison at a glance
| Product | Listed price | Condition | Core role | Power rating | Price bar |
|---|---|---|---|---|---|
| APC Smart-UPS XL SUM3000RMXL2U 3000VA 120V Rackmount Tower UPS New | USD 271.99 | New | Full 3000VA 120V UPS | 2850 W | |
| APC SMX120RMBP2U Smart UPS External Battery Pack Rackmount | USD 149.97 | Used | External battery pack for compatible Smart-UPS X systems | 120 W |
Where each product wins
- APC Smart-UPS XL SUM3000RMXL2U wins when you need a full UPS with 3000VA capacity, rack/tower mounting, and new-in-box condition.
- APC SMX120RMBP2U wins when you need a 2U battery expansion for an existing compatible Smart-UPS X setup and prefer a lower listed price.
- The listed price gap means you can choose either a complete UPS or a lower-cost runtime extender, depending on what your rack already has.
- If condition is the deciding factor, the SUM3000RMXL2U is the new unit; the SMX120RMBP2U is used but described as tested working.
Product notes
APC Smart-UPS XL SUM3000RMXL2U 3000VA 120V Rackmount Tower UPS New
This is a complete UPS rather than an add-on. It is listed as a modular 3000VA 120V UPS suited for servers, networking equipment, and critical IT infrastructure, and it supports both rackmount and tower installations. The unit is described as new in the original sealed box. If you are building out a rack or replacing an existing UPS, this option brings the main protection component in one purchase. The trade-off is its higher listed price of the two and the 25-inch length, which means you need to plan for rack depth or tower space. For a full UPS with 3000VA capacity, this is the straightforward pick.
APC SMX120RMBP2U Smart UPS External Battery Pack Rackmount
This is the expansion route. The SMX120RMBP2U is a used external battery pack in good, tested, working condition. It is designed to extend runtime for compatible Smart-UPS X systems and uses a 2U rackmount form factor. That makes it a fit when the UPS head is already in place and you need more battery capacity in a compact rack space. The pack carries a 120 W listed maximum power, and the included components are the pack itself: faceplate, batteries, and network management card are not included. That means you are buying the base expansion unit rather than a complete runtime kit, and you should plan for those absent items. At its lower listed price, it is a focused way to add battery capacity to a compatible system.
Final choice by use case
- Need a complete UPS for a server rack or network closet: APC Smart-UPS XL SUM3000RMXL2U, listed at $271.99.
- Need to extend runtime on a compatible Smart-UPS X system: APC SMX120RMBP2U, listed at $149.97.
- Prefer new condition and a full 3000VA power rating: APC Smart-UPS XL SUM3000RMXL2U.
- Prefer a lower listed price and already have the UPS head: APC SMX120RMBP2U.
