Guide to Uninterruptible Power Supplies

Guide to Uninterruptible Power Supplies

As we all know, blackouts happen to everyone…eventually.

And when they do, and your computer shuts down improperly, several bad things can happen…

  1. It puts unnecessary wear-n-tear on the hardware, which is a primary cause of most computer failures.
  2. It can potentially damage your data in a number of unpredictable ways.

And in a single moment, you could lose your entire day’s work…or worse.

Which is why…to keep your data safe, an Uninterruptible Power Supply (UPS) is a must-have item in any office or studio.

The problem is…finding the right UPS is an insanely frustrating process, as virtually EVERY educational resource on the subject uses highly-technical jargon that few consumers understand or care about.

And all most of us really want is a simple solution that offers:

  • the security of knowing you data and equipment are protected…
  • the satisfaction of knowing you found the best product for your money…
  • and the ease-of-use to just plug it in and forget about it.

So in today’s post, that’s exactly what I intend to help you find.

Let’s begin.  First up…

UPS vs Power Conditioners

Many times people fail to understand the difference between these two…often mistaking one for the other.

So let’s clear things up now by defining both:

  • An Uninterruptible Power Supply (UPS) – is a device with a backup battery that provides several minutes of power in the event of a blackout.  Typically they are used with computers, to protect sensitive data by allowing enough time for proper shutdown.
  • A Power Conditioner – is a device which filters and distributes power to various types of electronic gear such as studio monitors or audio interfaces.

Either one can offer various forms of power filtering such as surge protection and voltage regulation, but the primary distinction is that a UPS has a battery, while a power conditioner does not.

The 3 Categories of UPS

Depending on your budget, and the level of protection you need, there are 3 categories of UPS to choose from:

  1. Standby (offline)
  2. Online 
  3. Line-Interactive

Here’s how each one works:

1. Offline/Standby UPS

Cyberpower 350slg

The cheapest of the 3 designs…

standby UPS works under normal conditions by supplying your computer with AC power directly from the wall outlet.

Meanwhile…the battery sits on standby.

Then, when the power fails, the UPS detects the problem, and switches over to the battery.

While this method works well for most consumer electronics…

The problem is…the switching process causes a momentary lapse in power which is dangerous for certain highly-sensitive equipment.

This is why technically, the standby UPS is not considered a “true UPS”, as it is not truly “uninterruptible”.

The good news for us is…the typical lapse time (usually under 5ms, but sometimes as long as 20-100ms) is well within tolerance for normal desktop computers.

For critical applications however, it’s much safer to use this next design instead…

2. Online UPS

APC Online UPS

The best and most-expensive of the 3 designs is the online UPS (aka true UPS).

While once used only for ultra-expensive commercial operations, recent technology has made them somewhat affordable for consumer-use as well.

To supply truly “uninterruptible” backup power during blackouts, they use what’s known as the “double-conversion method“, which works like this:

  1. It takes AC power from the wall, and converts it to DC to charge the battery.  
  2. It takes the DC power from the battery and converts back to AC, which is used to power your computer.

So unlike the standby UPS which engages only when there’s a problem…the online UPS continuously filters power through the battery before sending it to your computer.

This has 2 BIG benefits:

  1. During a blackout, there is absolutely ZERO power interruption, because the computer is already running on battery power.
  2. Power to your computer stays perfectly clean and stable, because the output is always regulated by the battery.  

The only downside of this double conversion method is…it consumes far more energy than a typical standby UPS.

However…to increase energy efficiency, a similar online method known as “delta conversion” also exists…which delivers a portion of the power directly to the computer, rather than through the battery.

As you might expect, all this technology doesn’t come cheap…as typical online UPS’s cost several thousand dollars…which is way beyond the budget of average consumers.

Which is why for the vast-majority of people, I recommend this UPS design instead…

3. Line-Interactive UPS

Tripp Lite Smart LCD

While total blackouts are what we all fear most

In most places, the majority of power interruptions are actually momentary sags in power, commonly known as brownouts.

The problem is…standby UPS’s handle brownouts terribly, as they must repeatedly switch back and forth between AC and battery power to handle each dip.

This significantly shortens the battery’s lifespan by causing unnecessary drain, and annoys users by constantly tripping alarms.

Online UPS’s however, are great at handling brownouts, as they’re able to maintain a consistent voltage by continuously running off battery power.  But as you know…they’re also expensive.

Fortunately for us…Line-Interactive UPS’s handle brownouts just as well, and for a much cheaper price, using a special type of transformer which varies its output voltage in response to momentary power fluctuations.

So when the power dips, the transformer is still able maintain a stable output without switching over to battery power.

And since line-interactive UPS’s cost only slightly more than standby models…the general consensus is: they’re the best overall value of the 3 designs.

Up next…

Voltage Rating and Run-Time

voltage rating and run time

Regardless of design, the primary metric used to determine the expected output of a UPS battery is volt amp rating (VA).

In general, bigger VA numbers provide longer run-times…which is the number of minutes you have to shut down your computer after a power outage.

So what I recommend here is….to choose a UPS with the highest possible VA rating within your budget.

For home-use, the numbers typically range from 200VA – 1500VA.  And on average, this generally results in a minimum of 5-10 minutes of backup power.

However, other factors affect run-time as well, such as the battery condition, and load required to power all connected devices…so actual run times can still stretch far outside that range.

Other Features to Look for

With what we’ve covered so far, you can generally narrow down your search to a field of 3-4 possible models.

At which point…your final choice can be made based on the following 6 features:

  1. Performance Monitoring
  2. Available Connections
  3. Form Factor
  4. Noise
  5. User-Replaceable Batteries
  6. Equipment Protection Policy

1. Performance Monitoring

Cyberpower PowerPanel

A major problem with older UPS designs was the fact that they offered few details about their current health.

And often, problems were not discovered until after a power outage occurred and it was too late.

Recognizing this flaw, many of today’s newer units have added sophisticated monitoring systems…which inform of us immediately of potential problems.

For example, many high-end units include built-in visual displays, which show essential stats including run-time, battery health, etc.

Others include software programs that allow you to monitor those vital signs directly from your desktop.  Some are even smart enough to shut down your computer automatically when battery reserves drop too low.

2. Available Connections

UPS models for home-use typically offer a range of 5-8 outlets…

  • Some of which are connected to the battery for backup power.  
  • And some which are NOT, but still offer other standard features such as surge protection.

Others even offer protection for data cables as well, such as for ethernet and coaxial connections, which are must-have features for those who plan to use such peripherals.

3. Form Factor

Commonly known in the industry as “form factor“, this fancy term refers to nothing more than the outer-shape of the unit.

The 2 form factor options are:

  1. tower – which is smaller, meant as a stand-alone unit, and is primarily designed for simple home/office setups.
  2. rackmounted – is larger, designed for a standard rack shelf, and is primarily used for more complex commercial operations.

In virtually all cases, I recommend tower units for standard consumer use.

4. Noise

Depending on how you use your UPS, fan noise may or may not be an issue you’re concerned with.

For home recording, it’s a HUGE issue.  For offices…not so much.

As a general rule of thumb, smaller UPS don’t normally require a fan for cooling, but larger ones often will.

So if your work requires perfect silence, make sure your UPS is fan-free…unless of course you have a separate room for your computers, in which case it doesn’t matter.

5. User-Replaceable Batteries

Just like with any battery…the batteries in a UPS don’t last forever.

Most have a lifespan of around 3-5 years, and after that, there are 2 options:

  • replace the battery, or…
  • replace the entire UPS.  

Since it’s more cost-effective to just replace the battery, you ideally want a unit with user-replaceable batteries, so you won’t have to pay for servicing.

Unfortunately, most of the cheapest units won’t have this feature, which is why in the long-run, you’ll save money by avoiding them.

6. Equipment Protection Policy

No matter how great your UPS, there’s always the slight possibility that it could fail at the wrong time.

So…anticipating these rare events, certain brands will offer “equipment protection policies” on their units, to cover any damage resulting from their products malfunctioning.

And since these policies must cover anywhere between $50,000-$100,000, its typically only biggest brands that can afford to carry them.

Which is why in this next section, where I show you the top UPS models I recommend, I’ve limited the list entirely to the top 3 brands on the market.

And since the details vary considerably between each brand, I’ve also included a link the specific policies of each one.

The Top 3 UPS Brands

best ups brands

Without a doubt, the 3 biggest UPS manufacturers are:

  1. APC
  2. CyberPower
  3. Tripp-Lite

And while many of their top commercial units can cost upwards of $5000-$10,000 or more…