APC by Schneider Electric SRTL50RMBP1U-LI Smart-UPS Ultra 1U Lithium-Ion Rack Battery Pack
Overview
The APC by Schneider Electric SRTL50RMBP1U-LI is a 50V lithium-ion battery pack designed for 1U rack integration with compatible Smart-UPS Ultra systems. At 43mm tall (1U) and 560mm deep in a silver-grey enclosure, it slots cleanly into standard 19-inch rack cabinets without consuming extra rack space — a real advantage in dense server rooms or security head-end closets where every unit of rack real estate counts.
Lithium-ion chemistry is the defining feature here. Compared to traditional VRLA (valve-regulated lead-acid) battery packs, Li-Ion cells deliver higher energy density per kilogram, longer cycle life, and a substantially wider operating temperature range — all of which translate to lower total cost of ownership over the life of a UPS deployment. If you've managed a data center or security operations center with legacy lead-acid packs, the reduced replacement frequency and lighter handling weight are immediately felt.
Key Features
- 50V Lithium-Ion Chemistry: Li-Ion cells at 50V nominal carry more usable energy in a smaller footprint than equivalent lead-acid configurations. This means longer runtime extension per rack unit and fewer battery swaps over the UPS lifecycle — a direct reduction in maintenance overhead for facilities running 24/7.
- 1U Form Factor (432 × 43 × 560mm): At just 43mm tall, this pack occupies a single rack unit in a standard 19-inch cabinet. The 560mm depth fits most mid-depth and full-depth rack enclosures. Plan your rack layout with the depth in mind — shallow wall-mount enclosures under 600mm internal depth may not accommodate it without modification.
- Operating Temperature 0–40°C: Rated for full operation from freezing-adjacent conditions up to 40°C — the upper limit common in unconditioned telecom closets or equipment rooms with marginal cooling. If your installation environment regularly exceeds 40°C ambient, derate your expectations or add supplemental cooling before deploying.
- Storage Temperature -15–45°C: A -15°C lower storage limit is notably better than most lead-acid alternatives, which suffer permanent capacity loss when stored in cold environments. This matters for warehouse staging, cold-climate remote sites, or installations where equipment is stored before deployment over winter.
- 0–95% Relative Humidity (Operating and Storage): Wide humidity tolerance means the pack can operate and be stored in environments without strict humidity control — useful in industrial facilities, warehouses, and light-manufacturing security deployments where HVAC may be inconsistent.
- Operating Altitude to 3,048m (10,000 ft): Cleared for operation up to 3,048m above sea level, covering the vast majority of terrestrial deployments including high-elevation data centers and mountain-region facilities. Non-operating altitude extends to 15,240m, relevant for air-freight transit without requiring special pressurized packaging.
- Single Battery Unit Configuration: Ships as a single battery pack (1 pc), designed to pair directly with a compatible APC Smart-UPS Ultra host unit. Confirm your host UPS model supports external battery pack expansion and the number of packs it accepts before ordering multiples.
- Silver-Grey Rackmount Finish: The grey and silver color scheme matches standard APC Smart-UPS Ultra aesthetics — useful for client-facing installations or NOC environments where visual uniformity matters.
Integration and Compatibility
The SRTL50RMBP1U-LI (often searched as SRTL50RMBP1U LI) is engineered specifically for the APC Smart-UPS Ultra product family. Battery pack compatibility in UPS systems is not universal — the 50V bus voltage, connector interface, and communication protocol are all matched to specific host units. Before purchasing, verify the host UPS model explicitly lists this pack as a supported UPS battery expansion option. Using a mismatched pack can result in the host unit rejecting the battery or, worse, improper charge management that shortens cell life.
For rack planning, factor the 24.5 kg package weight into your floor-load calculations — dense battery configurations across multiple packs in a single rack can approach structural limits in older raised-floor environments. Distribute battery weight across multiple rack positions when possible, and confirm rack rail weight ratings before final installation. Review our APC power solutions lineup for compatible host units and complementary infrastructure.
Integration with network infrastructure and security systems depends on the host UPS's management card and communication capabilities — the battery pack itself is a passive power storage component. Runtime calculations, battery status monitoring, and graceful shutdown coordination are all handled at the host UPS level. For facilities running mixed IP surveillance cameras and network equipment on UPS-protected circuits, confirm the total connected load against the host UPS's rated VA/W capacity with this pack installed.
Frequently Asked Questions
Q: What UPS models is the SRTL50RMBP1U-LI compatible with?
A: The SRTL50RMBP1U-LI is designed for the APC Smart-UPS Ultra product family. Always verify the specific host UPS model explicitly lists this battery pack as a supported expansion option before purchasing — UPS battery compatibility is model-specific, not universal across a brand's lineup.
Q: What battery technology does the SRTL50RMBP1U-LI use, and why does it matter?
A: It uses lithium-ion (Li-Ion) chemistry at 50V. Compared to traditional VRLA lead-acid packs, Li-Ion offers higher energy density, longer cycle life, and a wider usable temperature range — translating to fewer replacements, lighter weight, and more reliable performance in environments with variable temperatures.
Q: Will the SRTL50RMBP1U-LI fit in a standard 19-inch rack?
A: Yes. The pack measures 432mm wide × 43mm tall (1U) × 560mm deep, fitting standard 19-inch rack rails. Verify your rack's internal depth accommodates 560mm — shallow wall-mount enclosures may not have sufficient clearance.
Q: What is the operating temperature range for the SRTL50RMBP1U-LI?
A: Operating range is 0°C to 40°C (32°F to 104°F). Storage range is -15°C to 45°C. If your equipment room regularly exceeds 40°C ambient, address cooling before deploying this unit to avoid premature capacity degradation.
Q: How much does the SRTL50RMBP1U-LI weigh, and are there floor-load considerations?
A: The packaged weight is 24.5 kg (approximately 54 lbs). When deploying multiple battery packs in a single rack, account for cumulative weight in floor-load planning — particularly in older raised-floor data center environments with lower structural ratings.
Q: Can the SRTL50RMBP1U-LI be used at high-altitude installations?
A: Yes. It is rated for operation up to 3,048m (10,000 ft) above sea level, covering the majority of terrestrial installation sites including high-elevation facilities. The non-operating altitude rating extends to 15,240m, supporting standard air-freight shipping without special handling.
The SRTL50RMBP1U-LI is one of those components that gets specified once and then largely forgotten — which is exactly the point. The 50V lithium-ion architecture means you're not scheduling annual capacity tests and swap cycles the way you would with lead-acid packs. In a security head-end or network operations center where battery maintenance is an afterthought until something fails during a power event, that operational difference is significant.
Technical Highlights:
- 50V Li-Ion Bus Voltage: Matched specifically to Smart-UPS Ultra host units — this isn't a generic voltage that works across battery families. The tight voltage pairing enables accurate state-of-charge tracking and optimized charge curves that extend cell longevity compared to open-spec designs.
- 1U × 560mm Depth Profile: The 432 × 43 × 560mm envelope is the real installation constraint to plan around. Width and height are standard 1U — depth is where integrators get caught. Budget 560mm of clear depth plus cable bend radius behind the unit in your rack layout before finalizing cabinet selection.
- 0–40°C Operating Range: Adequate for most conditioned spaces, but tight for telecom closets or edge deployments with marginal cooling. The storage range of -15°C to 45°C gives more headroom for staging and warehousing in cold climates without cold-soak damage to the cells.
Deployment Considerations:
- Confirm the host UPS model's maximum supported battery pack count before ordering multiples — Smart-UPS Ultra units vary in how many external packs they can manage simultaneously, and exceeding that count won't just waste money, it can trigger faults.
- At 24.5 kg packaged, two or more packs in a single rack column will approach or exceed floor-load limits in some older raised-floor environments — distribute vertically across multiple rack positions and check rail weight ratings before final install.
This pack is the right specification for security operations centers, network head-ends, and enterprise server rooms where the host UPS is already a Smart-UPS Ultra and the priority is extending runtime with minimal maintenance overhead — not for mixed-fleet environments where you need a universal battery solution.
