What to consider when buying a UPS?
What to consider when buying a UPS?
I reside in a region with frequent power interruptions. I'm reaching out to find the top UPS recommendation for someone with a PC similar to mine, based on the specifications listed here.
https://www.dicksmith.co.nz/dn/buy/...gZ...ugQAvD_BwE
The Delta Conversion Online UPS. Will cost a fortune, but hands down, the best UPS design there is (at least currently).
With that kind of hardware, you can forget "budget" and "value".
Simulated sine wave UPS - not going to happen, especially if you want "the best".
UPSes can output 3 different kinds of waveform:
1. square wave - cheapest of the three. ONLY good for robust hardware, like power generators and motors.
2. simulated sine wave (aka stepped-approximated sine wave) - mediocre price. Good for most home appliances (e.g fridge, washing machine, lights).
3. true/pure sine wave - high price. It is the same as you get out of the wall socket. ONLY waveform good for sensitive electronics, like medical equipment, TVs, PC PSUs.
So, you want to have true/pure sine wave UPS. Simulated sine wave UPS may also work, but it may not. More of that below;
When looking for an UPS, there are 2 things to look out:
1. Output waveform (square wave, simulated sine wave and true/pure sine wave)
2. Design (stand-by, line-interactive and online)
From here you can read about the differences between output waveform,
link:
https://suvastika.com/why-choose-a-sinew...erter-ups/
And here are explanations about the UPS design,
link:
https://www.eetimes.com/document.asp?doc_id=1272971
Waveform and design
For PCs, line-interactive UPS would be more than enough since PSUs can easily handle the 2ms to 5ms transfer time of line-interactive UPS.
As far as output waveform goes, true/pure sine wave UPS is best used. While simulated sine wave UPSes are cheaper than true/pure sine wave UPSes, PSUs with Active PFC aren't compatible with simulated sine wave. You might get simulated sine wave UPS running with Active PFC PSU but there can be some major issues. Here's what, how and why.
How do you know which PSUs have Active PFC and which ones don't?
Simple, every PSU that has 80+ certification (e.g 80+ Bronze or 80+ Gold) has Active PFC.
What is Active PFC?
Further reading:
https://en.wikipedia.org/wiki/Power_fact...near_loads
What can happen when using simulated sine wave UPS with Active PFC PSU?
When simulated sine wave UPS switches over to the battery power, one of 3 things can happen:
1. UPS displays error resulting PC to shut down immediately.
2. UPS shuts down resulting PC to shut down immediately.
3. UPS switches to battery power resulting PC to power off from UPS (PC stays on).
Why it happens?
Simulated sine wave UPS produces a zero output state during the phase change cycle resulting in a power “gap”. This gap may cause power interruption for active PFC PSUs when switching from AC power output to simulated sine wave output (battery mode).
What to do next?
As stated above, your PC can run off from simulated sine wave UPS but be prepared when you face issues with it. When issues do rise, your best bet would be returning the simulated sine wave UPS and getting true/pure sine wave UPS. Or you can go with true/pure sine wave UPS off the bat.
Wattage
As far as UPS wattage goes, you need to consider the power draw of your PC and monitors. Maybe speakers and wi-fi router too if you plan to plug those into the UPS as well. Though, printers, scanners and other such hardware (full list on your UPS manual) don't plug to the UPS since their startup power draw is way too much for UPS to handle and you can fry your UPS.
Taking PSU's max wattage as a baseline is good idea since it will give your UPS more headroom and you can get longer runtime out of your UPS. Since your PSU is 1000W, at least one monitor is added on top of it. Depending on the monitor size, they use between 23W to 52W. Wi-fi routers don't consume much power. For example, my Cisco EPC3940L consumes 12V at 3A which means 36W.
Good UPS brands to go for are CyberPower, TrippLite and APC. While there are other UPS brands as well, those three are the best out there.
Note: The more powerful UPS you have, the longer UPS can keep your PC running before it's battery is empty.
With all that being said, good UPS to go for is: CyberPower CP1600EPFCLCD 1600VA/1000W (true/pure sine wave, line-interactive) UPS;
specs:
https://www.cyberpower.com/eu/en/product...600epfclcd
store link:
https://www.dicksmith.co.nz/dn/buy/flash...6-6199592/
My 2x PCs are also backed up by UPSes, 1x UPS per PC. I have two of these in use: CyberPower CP1300EPFCLCD (1300VA/780W, true/pure sine wave, line-interactive),
specs:
https://www.cyberpower.com/hk/en/product...300EPFCLCD
My UPSes are actually predecessor of CP1600EPFCLCD and since mine are already 6 years old, i'm planning to replace them with the very same, new version, i linked for you. But i'm going with 1350VA/810W ones.
Thanks for your understanding. Since I'm not a tech expert, I figured it was best to consult someone else. I wouldn't have wasted time and money trying it alone. Appreciate your help.
Just a quick question: Would a higher wattage (over 1000W) extend battery life during an outage?
Though, the concept of a line-interactive topology is to keep the PC running as long as you can save your work and then shut it down safely. Typically, around 5 minutes works well, and possibly even 10 minutes. For example, the CyberPower 1600VA/1000W UPS offers a full load runtime of about 2.6 minutes, while at half load (500W) it lasts around 9.7 minutes.
However, a UPS isn't a battery that powers your PC continuously. If you need constant power, consider purchasing a gasoline or diesel generator that supplies electricity when the main supply is down or when an online UPS is active.
Additionally, the CyberPower PFC Sinewave series doesn’t offer a higher UPS capacity than its 1600VA/1000W model. For increased power needs, explore double-conversion or delta-conversion online UPS options. These models start in the kW range and extend up to MW levels (1000W = 1kW, 1000kW = 1MW). Online UPS systems are typically used to protect entire server facilities.
The on-line UPS setup continuously draws power from the battery while using mains to recharge it. When the main electricity fails, there’s no interruption in power transfer—only the battery drains. The drawback is that constant battery use can shorten its lifespan. On-line UPSes usually have multiple batteries, allowing replacement without interrupting power supply to servers.
Aeacus has provided clear explanations. The important factor is the wattage, which only shows the device's output capacity and not how long it can actually supply power. You should view the watt value like a circuit breaker setting—it doesn’t directly indicate the duration of operation.
Estimating how long a UPS will last often involves checking the battery type it uses. Since replacements typically occur around three years, it’s wise to verify if the device relies on unusual or expensive batteries.
The most common consumer UPS systems use either 1 or 2 12-volt, 9Ah batteries. These can deliver about 108 watts for one hour. Theoretically, if your computer uses only 108 watts, it would last an hour; at 1080 watts, it would run for just six minutes. The calculation becomes more complicated because higher power draws generate more heat loss.
In practice, it’s better to choose a UPS with a wattage higher than what your equipment actually needs. Then, when comparing run times, add the total amp hours from the batteries. This gives a more accurate estimate.
For servers in small data centers, you often see 4 9Ah batteries used. However, some discussions suggest adding large external lead-acid batteries with high amp-hour ratings. While this can work, UPS components are built to handle limited usage periods, so overuse will eventually reduce their lifespan. A more sustainable long-term solution is considering solar-powered battery systems and charging them from the grid instead of relying solely on solar panels.