APC by Schneider Electric SRT72BP External Battery Pack for Smart-UPS SRT Systems
Overview
The SRT72BP is a 72V DC external battery expansion pack designed to connect directly with APC Smart-UPS SRT on-line UPS systems, extending runtime beyond what the internal batteries alone can deliver. If your facility runs critical loads — servers, network infrastructure, access control panels, or surveillance recorders — where even a brief power gap is unacceptable, adding the SRT72BP buys the extra runtime margin to ride out longer outages or execute a controlled shutdown. The unit operates at 72V DC on both input and output, matching the internal bus voltage of compatible SRT-series UPS units, so integration is direct without conversion losses. At 17.008 inches tall, 3.3 inches wide, and 23.4 inches long, the SRT72BP fits in a standard rack bay alongside or beneath the host UPS, keeping your power infrastructure consolidated in the same footprint.
Key Features
- 72V DC Input and Output: Voltage matching the SRT on-line UPS internal bus means no conversion stage between the pack and the UPS — power transfers cleanly and efficiently, with no additional regulation circuitry required between them.
- Rack-Optimized Form Factor (17.008" H × 3.3" W × 23.4" L): The slim 3.3-inch width means the SRT72BP occupies minimal rack real estate. In dense equipment rooms where every rack unit counts, this profile lets you stack runtime capacity without sacrificing switch or server space.
- Direct SRT On-Line UPS Compatibility: Designed specifically for APC Smart-UPS SRT on-line systems — not a universal add-on. Pairing with the correct host UPS ensures the battery management firmware recognizes and monitors the pack, preventing unmanaged charging cycles that shorten battery life.
- RBC141 Battery Kit Compatibility: When replacement time comes, the SRT72BP accepts the RBC141 battery kit, which is also available in PowerSWAP format. Two battery kits or PowerSWAPs are required per pack — knowing this upfront lets you budget accurately for future maintenance cycles rather than discovering mid-replacement that you need a second kit.
- Black Finish: Standard black chassis blends with APC SRT host units and typical rack environments — no cosmetic mismatch in customer-facing or co-location deployments where rack aesthetics matter.
Integration and Compatibility
The SRT72BP is built exclusively for use with APC by Schneider Electric Smart-UPS SRT on-line UPS systems that operate on a 72V DC battery bus. Before purchasing, confirm the host UPS model number supports external battery pack expansion — not all SRT variants do, and connecting an incompatible pack can void UPS firmware protections. This unit is not compatible with Back-UPS, Smart-UPS SMT, or Smart-UPS SMX lines, which operate at different voltages and use different battery interfaces.
For facilities building out uninterruptible power supply infrastructure to protect network closets, IDF/MDF rooms, or edge surveillance nodes, the SRT72BP pairs naturally with rack-mounted SRT UPS units feeding PoE network switches and network video recorders. Consult your UPS runtime planning guide to calculate how many battery packs are required for your target hold-time at your actual load wattage — runtime scales with load, and undersizing the battery string is the most common deployment error in critical infrastructure builds.
Frequently Asked Questions
Q: What UPS systems is the SRT72BP compatible with?
A: The SRT72BP is designed for use with APC Smart-UPS SRT on-line UPS systems that use a 72V DC battery bus. It is not compatible with Back-UPS, SMT, or SMX lines. Verify your specific SRT model supports external battery pack expansion before ordering.
Q: How many battery kits does the SRT72BP require for replacement?
A: Two battery kits or two PowerSWAPs are required per SRT72BP unit. The RBC141 battery kit is compatible and is also available in PowerSWAP format for hot-swap replacement without shutting down the UPS.
Q: What are the physical dimensions of the SRT72BP?
A: The SRT72BP measures 17.008 inches high, 3.3 inches wide, and 23.4 inches long — designed to fit in a standard equipment rack alongside compatible SRT UPS units.
Q: Does the SRT72BP include batteries, or are they sold separately?
A: The evidence available does not confirm whether batteries are pre-installed or sold separately. Contact pre-sales engineering to confirm exact package contents before ordering if runtime calculations depend on immediate battery availability.
Q: What input and output voltage does the SRT72BP operate at?
A: The SRT72BP operates at 72V DC on both input and output, matching the internal battery bus of compatible Smart-UPS SRT on-line systems.
The SRT72BP is a purpose-built battery expansion unit — not a general-purpose add-on. The 72V DC bus architecture means it integrates directly with the SRT host UPS without any intermediate voltage regulation, which keeps the charging and discharge management entirely within the UPS firmware where it belongs. If you are sizing a critical infrastructure deployment and need to extend runtime past what the internal battery provides, this pack is the correct path for SRT-family systems.
Technical Highlights:
- 72V DC Bus Voltage: Matches the SRT UPS internal bus exactly — no conversion losses between the pack and the inverter stage, and the UPS battery management system monitors the external pack as a native extension.
- Rack Form Factor (3.3" W × 23.4" L × 17.008" H): Slim enough to fit in a standard rack bay without displacing active equipment — relevant when you are adding runtime capacity to an already-dense IDF or network closet.
- RBC141 Replacement Kit: Available in both standard and PowerSWAP formats — PowerSWAP allows battery replacement under load, which matters for 24/7 environments where a maintenance window for a cold swap is not practical.
Deployment Considerations:
- Two RBC141 kits are required per SRT72BP at replacement time — budget for both upfront and store a spare set on-site to avoid extended downtime waiting on parts when a cell degrades.
- The SRT72BP only functions with compatible Smart-UPS SRT on-line units — confirm your host UPS model explicitly supports external battery pack expansion before installation, as not all SRT variants expose the external battery bus.
The SRT72BP is the right call for network closets and surveillance head-end rooms running APC SRT on-line UPS units where the base runtime is insufficient for the site's target hold-time — specifically environments with extended generator start delays or facilities requiring a full controlled-shutdown window across multiple servers and recorders simultaneously.
