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Quick answer
A UPS (uninterruptible power supply) is best for short outages, voltage blips, and graceful shutdowns. It is not a giant portable battery for running appliances for hours. Choose by load watts, runtime needs, outlet type, battery replaceability, and whether you need AVR or pure sine wave.
| Use | Good fit? |
|---|---|
| Router and modem | Yes |
| Desktop computer safe shutdown | Yes |
| NAS and network gear | Yes |
| Monitor for short runtime | Yes |
| Home office gear | Yes |
| Fridge or freezer | Usually no |
| Space heater or kettle | Absolutely not |
| Sump pump | No |
| Whole-home backup | No |
What a UPS is good for
- Router and modem — keeps the internet chain alive during short outages. See keep Wi-Fi on during a power outage.
- Desktop computer — gives enough time to save work and shut down properly. Prevents data loss and filesystem corruption.
- NAS — protects against data corruption during writes. A UPS with USB shutdown signalling lets the NAS shut down safely without intervention.
- Monitor — short runtime is fine for wrapping up what you are doing.
- Home office gear — keeps a work setup running for a few minutes to save files, send a last email, and shut down properly.
- Graceful shutdown — the real value of a UPS is not runtime, but giving your equipment time to shut down safely instead of losing power instantly.
What a UPS is bad for
- Fridges and freezers — unless specifically rated for the compressor surge and runtime. A standard 600 VA UPS might last 10 minutes on a fridge. Not useful. A tiny UPS is not a fridge plan.
- Space heaters and kettles — these are pure resistive heating loads at 1,500W. They will either overload the UPS or drain it in under a minute.
- Sump pumps — motor startup surge can trip UPS overload protection. Sump pumps need a different approach. See sump pump battery backup.
- Whole-home backup — a UPS is not sized for an entire panel. That requires a generator with transfer equipment or a large standby system.
Specs that matter
UPS specs that matter
| Spec | Why it matters | Look for | Marketing sludge to ignore |
|---|---|---|---|
| VA vs watts | VA is the apparent power rating; watts is the real power your devices draw. Not all VA is available as watts. | Watts rating on the spec sheet. A 1,000 VA UPS may only deliver 600–800W. | VA claims without the watts number. |
| Runtime curve | Runtime drops fast as load increases. A UPS rated for 30 minutes at 50% load may last 5 minutes at 100% load. | Runtime table in the manual showing minutes at different load percentages. | "Up to X hours" without stating the load. |
| Output waveform | Pure sine wave is better for sensitive electronics, motors, and some power supplies. Simulated sine wave works for most basic electronics. | Pure sine wave for NAS, computers, or any sensitive gear. | "UPS optimized waveform" without clear classification. |
| AVR (automatic voltage regulation) | AVR corrects minor voltage sags and surges without switching to battery, saving battery life for real outages. | AVR with boost and trim ranges stated. | Surge-only protection claimed as AVR. |
| Replaceable battery | UPS batteries wear out every 3–5 years. A replaceable battery extends the life of the unit. | User-replaceable battery with readily available replacement pack. | Sealed unit that must be thrown away when the battery dies. |
| Backed-up outlets | Not all outlets on a UPS are battery-backed. Some are surge-only. | Number of battery-backed outlets plus surge-only outlets. Labels on the unit. | Total outlet count without specifying which are backed up. |
| Surge protection | Protects equipment from voltage spikes. All UPS units include this, but ratings vary. | Joule rating and response time. | "Best surge protection" without the joule number. |
| Software / shutdown support | USB or network signalling lets a computer or NAS shut down automatically when battery is low. | USB port, supported software (PowerChute, NAS compatibility list). | "Shutdown support" without listing compatible OS or NAS brands. |
| Canadian certification marks | CSA, cUL, or cETL marks indicate the product has been tested to Canadian safety standards. | CSA, cUL, cETL on the box or unit. | CE mark only — CE is self-declaration, not Canadian certification. |
UPS vs power station
The key difference: a UPS switches to battery instantly (milliseconds), which is essential for electronics that reboot on power loss. A portable power station usually does not switch instantly and is better for longer runtime with manual setup.
For a full breakdown, see UPS vs power station. Quick summary:
| Feature | UPS | Portable power station |
|---|---|---|
| Switchover | Instant | Usually manual (some models have EPS/UPS mode) |
| Best for | Router, computer, NAS | Phones, laptops, lights, appliances |
| Runtime | Usually short (5–30 min at typical loads) | Often longer (hours to days for light loads) |
| Portability | Not designed for it | Designed for it |
| High-draw appliances | No | Some — depends on inverter and capacity |
Minimum / better / overkill
UPS minimum / better / overkill
| Decision | Minimum | Better | Overkill |
|---|---|---|---|
| Router and modem only | 400 VA / 250W UPS | 600 VA / 350W with AVR | 1,000+ VA UPS |
| Desktop safe shutdown | 600 VA / 350W UPS | 850 VA / 510W pure sine wave with USB shutdown | 1,500 VA with network card |
| Home office (computer + monitor + router) | 850 VA / 510W | 1,000 VA / 600W pure sine wave with AVR | 1,500 VA + separate UPS for network gear |
| NAS and network gear | 600 VA / 350W with USB shutdown signalling | 850 VA / 510W pure sine wave with AVR | 1,000+ VA with network management card |
| Appliances (fridge, sump, etc.) | Not a UPS job. See portable power station or generator. |
Safety notes
Canadian context
Canadian context
UPS units are widely available in Canada through major electronics retailers and online. A few Canadian-specific considerations:
- Cold weather: UPS batteries lose capacity in cold temperatures. If your UPS is in a garage, basement, or unheated area, expect shorter runtime during winter outages.
- Certification: Look for CSA, cUL, or cETL marks. These indicate the product meets Canadian electrical safety standards. CE mark alone is not Canadian certification.
- Battery recycling: UPS batteries must be recycled properly. Many Canadian electronics retailers accept lead-acid batteries for recycling. Check your provincial electronics recycling program.
- AVR for flaky power: If you are in an area with frequent brownouts or voltage fluctuations (common in some rural and older urban areas), AVR can save your UPS battery for when it is actually needed.
Hidden costs to consider
- Battery replacement — UPS batteries last 3 to 5 years. A replacement battery pack can cost 30 to 60 percent of the original unit price. Factor that into the total cost of ownership.
- Shipping weight — UPS units are heavy (20 to 50+ lb for larger models). Shipping costs for returns or warranty claims can be significant if the unit needs service.
- Battery recycling fees — some provinces charge recycling fees on lead-acid UPS batteries. Not always included in the purchase price.
- Network management cards — if you need remote monitoring or automatic shutdown for multiple servers, the management card is often sold separately.
- Extended warranty — standard UPS warranties are often 2 to 3 years. Extended warranties add cost but may be worth it for critical equipment.
- Replacement frequency — unlike some electronics that last a decade, a UPS is a consumable device. Budget for full unit replacement every 5 to 8 years.
Claims to treat carefully
- “Up to X hours runtime” — runtime claims without a stated load are meaningless. A UPS that runs a 10W router for 10 hours may only run a 200W desktop for 15 minutes. Check the manufacturer runtime curve at your actual load.
- VA-only marketing — some UPS listings lead with VA and bury or omit the watt rating. Compare watts, not VA, to your device draw.
- “AVR” protection that is just surge suppression — true AVR (automatic voltage regulation) actively corrects voltage variations. Simple surge protection is not AVR.
- App features over basic reliability — a UPS with a smartphone app is convenient. A UPS without reliable runtime data, user-replaceable batteries, and proper outlet labelling is not.
- “Pure sine wave” on budget UPS units — some budget models claim pure sine wave but deliver a stepped approximation. Check whether the specifications confirm pure sine wave or say “simulated.”
- “Medical-grade” claims — no standardised definition exists for this in UPS marketing. It does not replace certified medical equipment power requirements.
What to check before buying
Before choosing a specific UPS model, verify these details against current product data:
- Runtime curves from official spec sheets, not marketing estimates
- Canadian certification marks (CSA, cUL, cETL) confirmed on the unit or packaging
- Battery replacement cost and availability at Canadian retailers
- AVR and waveform claims checked against technical documentation
- Current Canadian price and availability — prices change
- Whether the model fits your specific load needs (router-only vs desktop vs NAS)
Methodology
Methodology
This guide provides a category-level buying framework for UPS units based on typical consumer UPS specs, common load profiles, and Canadian electrical safety context. No specific UPS brands or models are reviewed or ranked.
Model-level picks require verified runtime curves and Canadian certification evidence before any product is named. Product availability, certifications, and prices change, so verify the current model before buying.
Related guides
Related ReadyHome guides
Frequently asked questions
What size UPS do I need?
Add up the watts of everything you want to back up, then pick a UPS rated for at least 20–30% more than that total. For a router and modem (20–40W total), a 400–600 VA UPS is plenty. For a desktop computer with monitor (200–400W), aim for 850–1,000 VA.
How long will a UPS run a router?
Most small UPS units will run a router and modem (15–30W total) for 1–4 hours depending on the UPS size, load, and battery condition. Larger UPS units can run network gear for 4–8 hours. Check the manufacturer runtime chart at your actual load.
Can a UPS run a fridge?
Generally no. A typical fridge draws 100–200W running with a compressor startup surge of 600–1,200W. Most consumer UPS units cannot handle the startup surge or sustain runtime for more than a few minutes. If you need fridge backup, look at portable power stations or generators.
What is the difference between VA and watts?
VA (volt-amps) is the apparent power rating. Watts is the real power the UPS can deliver. For most consumer UPS units, the watt rating is 60–80% of the VA rating. Always compare watts to your device watt draw, not VA.
Is pure sine wave UPS worth it?
If you are powering a computer with an active PFC power supply, a NAS, or any sensitive electronics, yes — pure sine wave is safer and more compatible. If you are only powering basic electronics with standard power supplies (router, modem, basic desktop), simulated sine wave usually works fine.
How often do UPS batteries need replacing?
Every 3–5 years depending on usage, temperature, and discharge cycles. Replace the battery when the UPS starts beeping more frequently during self-tests or runtime drops noticeably. Use the replacement battery pack recommended by the manufacturer.
Official sources used
Public Safety Canada / Canada.ca
Canadian household outage risks and 72-hour preparedness framing.
Health Canada
Recognized Canadian certification marks and electrical product warnings.
Buying electrical products online
Health Canada
Risks of uncertified electrical products from online marketplaces.