A UPS power supply usually sits between a computer that is being powered and the mains in a wall socket, plugged into each with separate cables. They are similar to a Fiamm battery, though those use USB. Depending on what it is intended to be used for and its power capacity, the typical office or home UPS battery backups are generally compact and small “smart” units, built around high-drain rechargeable power cells.

The traditional UPS units would be VRLA (lead-acid) batteries, yet the developments linked to lithium-ion technology have led to Li-ion cells becoming the more widespread and more popular component in the modern UPS systems.

Lead-acid or VRLA batteries are typically low-maintenance, yet basic and reliable UPS power-supply workhorses that usually have a 5-year lifespan. VR in VRLA represents Valve-Regulated, which means that a VRLA battery has an automatically operated, built-in vent system that controls gas build-up that gradually builds up at specific points in a battery’s charge-drain cycle. This function is important and triggered by the internal-pressure sensors. Like many of the aspects of the VRLA cell-types, they perform at their best when in a temperature-controlled and dry environment. This usually includes a centrally-heated room found in your typical office or home.

In contrast, the Li-ion UPS battery is usually lightweight and a lot more compact. They also come with various power-management features. These include advanced voltage and charge balancing. Most brands also provide a longer lifespan when compared to the lead-acid batteries, which typically makes them a far more economical choice. However, upfront the Li-ion UPS units are priced according to their production costs which are much higher, which means the VRLA-based units are a cheaper option for the initial buy-in.

The third option for UPS batteries is known as VLA or flooded/wet cell types. These units are not as widely available as a purchasable option in off-the-shelf or high-street UPS systems. This has to do with the intended usage of these systems which are for highly specific environments and applications. To begin with, the chemical make-up of these units makes them potentially hazardous and they need to be stored in a battery storage saferoom that is entirely separate from the rest of the building. These units also require frequent user maintenance when it comes to topping up the distilled-water levels along with constantly monitoring their calibration and equalisation data.

While this might make the VLA batteries impractical for most office and home environments, the wet cells offer a distinctive advantage for certain cases. This can include large-scale server centres when outstanding long-term stability and reliability are the main requirements above practicality and convenience.

Over and above the housing and the battery itself, the UPS power supplies also include other features that will depend on the actual model and cost of a unit. Some of these elements can often include:

  • Power surge, deep discharge, low voltage or/and temperature protection
  • Advanced onboard software that monitors the performance
  • Data-reading functionality and management card-slots
  • Graphical calibration interfaces
  • OLED/LCD readout panels and display screens
  • Different types of external hardware and connectivity I/O expander output/input options
  • Various outlets and power sockets
  • Various IP ratings