Understand dc UPS Systems for Mission-Critical Applications

Summary

In a world shaped by digital transformation, AI and smart manufacturing, uninterruptible power supply (UPS) systems have become essential to maintaining operational continuity. A reliable 12 V, 24V or 48 Vdc backup is crucial for safeguarding sensitive systems and processes across many industries, including industrial automation, edge computing, vision systems, infrastructure, energy and process technology, health care and more.

As designed, dc UPS systems deliver uninterrupted power to dc-operated devices during outages, voltage drops or voltage flicker. Each system typically combines a charging and control unit with a dedicated energy storage module—such as Li-Ion, LiFePO₄ batteries or ultracapacitors, to ensure fast, reliable backup.
These systems protect critical components like industrial PCs, Industrial Internet of Things (IIoT) gateways, motor drives, sensors, security infrastructure and medical devices. They help maintain uptime, prevent data loss and ensure process continuity.

Available for 12 V, 24 V and 48 Vdc applications (optionally with ac or dc input), UPSs are ideal for decentralized environments where they’re directly integrated into machines or control panels to keep operations running even during unexpected power events.
 

Choosing energy storage technologies

Selecting the right energy storage technologies for dc UPS systems is essential due to varying requirements such as environmental conditions, backup durations, as well as lifespan and maintenance considerations—all of which directly impact the total cost of ownership (TCO). Different technologies (Figure 1) provide different benefits:
 
Lithium iron phosphate (LiFePO₄). LiFePO₄ batteries offer outstanding safety and lifecycle performance. With up to 6,000 full charge/discharge cycles, they provide long-term stability, minimal maintenance and resistance to thermal runaway, which makes them ideal for mission-critical industrial and medical installations. Their inherent safety profile ensures minimal fire or explosion risk, which delivers peace of mind where uptime and security are paramount. They also offer long backup durations that make them a dependable choice for extended outages. With a lifespan of at least 10 years, this battery technology offers a low TCO.

Lithium-Ion (Li-Ion). Known for high energy density and compact form factors, standard Li-Ion batteries support space-constrained applications. While their efficiency is notable, they are more sensitive to temperature extremes and overload conditions and generally offer lower cycle life than LiFePO₄. They are best suited for applications where compact size and cost sensitivity are more important than maximum durability or resistance.

Supercaps (Ultracapacitors). With an extremely long service life of up to 500,000 cycles and fast charge/discharge capability, supercaps—based on the principle of electric double layer capacitor (EDLC)—provide instant, powerful energy boosts. Energy storage solutions with supercaps are ideal for short to medium duration bridging periods. They are maintenance free and very durable, which makes them perfect for applications that require a set-and-forget solution with minimal upkeep.

System designs

System designs are tailored for specific environments and application requirements. These designs include modular dc UPS systems, all-in-one DIN-rail-mounted systems and IP-protected systems for harsh environments.

Modular dc UPS systems. Modular architectures combine UPS electronics and battery packs in scalable configurations available as open-frame designs or in DIN rail enclosures. These systems allow flexible sizing and energy expansion that supports a wide range of power needs. Modular systems can be configured with different energy storage technologies that offer application-specific adaptability and easy integration.

All-in-one DIN-rail-mounted dc UPS systems. Compact, space-saving and installation-friendly, DIN-rail UPS units integrate energy storage and UPS functionality in a single enclosure. Optimized for industrial automation and control environments, they support rapid deployment into control cabinets. The dc UPS systems available with integrated LiFePO₄ or supercap energy packs are characterized by a long service life and low TCO.

IP-protected systems for harsh environments. Designed for outdoor or rugged use, IP65/67-rated dc UPS systems resist dust, water and mechanical stress, which makes them ideal for infrastructure, edge deployments or remote field installations. Their robust construction ensures reliable operation under extreme conditions—from factory exteriors to remote sensor and measuring stations.
 

Final thoughts

The choice of dc UPS system depends on specific operational demands, ranging from industrial manufacturing to medical diagnostics and edge-based systems. With modular flexibility, integrated DIN-rail options and rugged outdoor solutions, today’s dc UPS offerings deliver tailored reliability where it’s needed most.

Combining high-performance energy storage options like safe and long-lasting LiFePO₄ batteries, power-dense Li-Ion cells or maintenance-free supercaps, users can deploy backup systems that ensure uninterrupted performance with minimal risk. In an increasingly connected and automated world, these technologies are more than a safeguard—they are a strategic foundation for reliable, uninterrupted operation.

_{This feature originally appeared in the May 2025 edition of Automation.com Monthly.}