How to Choose a UPS for Load Shedding
Load shedding is a fact of life for South African homes and businesses, and an unplanned outage mid-task — mid-invoice, mid-video-call, mid-save — is genuinely disruptive. A UPS (uninterruptible power supply) bridges that gap. Here's how to choose one that actually covers what you need it to.
UPS vs inverter — what's the difference?
A UPS is designed to switch over instantly (or near-instantly) when the power drops, keeping sensitive electronics like a PC or router running without so much as a flicker, but usually only for minutes rather than hours — it's built for a brief bridge, not to power your home through a full load shedding stage. An inverter (paired with a battery bank) is the larger-scale option, built to keep a wider range of appliances running for longer stretches. If you just need your desk to keep working through a load shedding stage, a UPS is usually the right, more affordable answer; if you want to keep lights, a fridge or other appliances running for hours, that's an inverter setup.
Work out what you actually need to protect
Start by listing what must stay on: a desktop PC and monitor draws meaningfully more power than a router and modem alone. A UPS is sized in VA (volt-amps) or watts — the higher the figure, the more it can power and the longer it'll run a given load. As a rough guide, a small UPS is enough to keep a router and modem online for hours (they draw very little power), while a desktop PC and monitor will drain a similarly-sized UPS in a matter of minutes. If in doubt, oversizing slightly gives you more comfortable runtime than you'd get from cutting it too close.
Be realistic about runtime
A UPS is not a substitute for an inverter or generator when it comes to runtime — most desktop/office UPS units are built to bridge minutes, not hours, giving you time to save your work and shut down cleanly, or to ride out a brief blip rather than a full load shedding stage. If you need genuinely long runtime, that's a sign you need a larger inverter/battery setup rather than a bigger UPS.
Line-interactive vs online double-conversion
Most home and small-office UPS units are line-interactive — good value, and more than adequate for protecting a PC or networking gear from outages and voltage dips. Online double-conversion UPS units cost more but supply genuinely clean, constant power with zero switchover time, which matters more for sensitive server or networking equipment than for a typical desktop setup.
Battery life and replacement
A UPS's battery is a wear item — expect to replace it every few years depending on how often it's called on, which in a load-shedding context can be often. Check whether the model you're considering has a user-replaceable battery, since that keeps the unit useful for years rather than needing full replacement once the battery degrades.