Here’s how to use a home inverter as a UPS for a computer:
You can use a home inverter as a UPS for a computer, provided that it meets the right specifications and standards.
It needs to supply the right AC frequency (60 Hz in the U.S. and 50 Hz in most other countries).
It also has to maintain a switching time of five milliseconds or less.
So if you want to learn all about using a home inverter to provide power backup for a computer, then you’re in the right place.
What Is a Home Inverter?
Today’s question is rather technical, and in order to explain how a home inverter might work as a UPS, we really need to nail down what some of this technology is and how it works.
Allow me to start with an inverter.
An inverter is a device that is designed to switch a current from DC to AC.
What does that mean?
Well, electricity, for the most part, can travel in one of two forms: AC and DC.
AC stands for alternating current, and it’s the electricity delivery technique that was championed by Nikola Tesla.
To keep from getting too technical, an AC current has a mechanism in it that basically switches the magnetic orientation of the current at regular intervals.
Basically, this allows the current to move in short, fast bursts, and as a result, it takes less energy to push a lot of AC current over short and medium distances.
Because of this, the current in your house is AC.
DC, on the other hand, stands for direct current.
This is a flow of electricity that doesn’t oscillate at all.
It just flows consistently.
But, since it lacks the advantages of the AC current, it takes more energy to push electricity through short and medium wires.
To clarify, short and medium distances cover anything under 300 miles, so the vast majority of electrical sources that you might see or deal with are going to be AC.
Still, there are some advantages to using DC, especially in computer systems, which I’ll explain in the next section.
The point is that an inverter can switch from one to the other.
As for a home inverter, it’s just an inverter that is designed for residential use.
You can also get inverters for automobiles, and you can get industrial inverters.
Each would be designed for currents of different strengths, but the general principle is the same.
There’s one more thing to know, though.
In modern marketing, “home inverter” is a term to describe something that is actually quite a bit more than just an inverter.
Devices marketed in this way usually work as power backups for devices in your house.
I’ll get into some of the technical aspects of this a little later.
Why Do Computers Need DC?
First, let’s talk about DC currents.
They’re not as good for pushing electricity efficiently, and the power running through your house is already AC.
Because of that, most home appliances are also designed for AC currents.
Computers, however, prefer a DC current.
That’s because the oscillation of the AC current can actually create magnetic interference that confuses the tiny, sensitive circuits in a computer.
So, most computerized devices prefer a DC current.
This is why laptop chargers have that thick brick in the middle of the cable.
It actually serves to convert the AC current from the wall into a DC current for the laptop.
The power supply in a desktop computer works similarly.
Additionally, a lot of batteries prefer to charge from a DC current.
The stability of the DC current is better for the battery charge and reduces wear and tear on the battery when it does charge.
This is actually why backup power supplies for homes are often called home inverters.
The device needs to convert the AC power into DC in order to charge the backup battery.
But in order to power most home appliances, the device has to invert the current back into AC, and that’s why they carry the name “home inverter.”
A little later, we’ll talk about how all of this works between a home inverter and a computer, but we still need to go over UPS systems.
What Is a UPS? (2 Things)
A UPS is very different from a home inverter, even though they serve somewhat similar goals.
UPS stands for uninterruptible power supply.
The gist is that this device provides backup power in the case of a general outage, and it’s designed specifically to provide that power to computer systems.
UPS devices are very common in data centers, for example.
In most cases, a UPS is not designed to run the computers for very long—just a few minutes until everything can switch to an alternative power source.
Most data centers have powerful backup generators.
The UPS is just there to prevent the computers from running out of juice while the whole place switches from standard power to the backup generators.
But, you can get a UPS that lasts considerably longer.
It all depends on the design.
What matters is that the UPS is primarily there to prevent a computer from suddenly losing power, even if the utility power supply is unexpectedly lost.
#1 Run Time
When considering a UPS, run time matters a lot.
Each UPS is different, but regardless, it can only store so much charge.
The amount of charge stored depends on the UPS design, and that’s why some last for minutes while others can last for hours.
When you’re shopping for a UPS, the manufacturers typically provide estimates of how long a UPS can keep computers running based on how much power they draw.
Naturally, a UPS for a home computer setup would be very different from one that could keep a whole data center operating.
#2 Batteries vs. Capacitors
Another important factor for a UPS is batteries and capacitors (and this applies to home inverters too).
A UPS that only has to run for a few minutes actually doesn’t need a battery.
Instead, it can use a capacitor.
A capacitor is a device that can store an electric charge, but only while it has a constant supply of power.
So, if a capacitor loses access to fresh power, it will start to discharge.
In a way, it’s like a battery, but it usually won’t last as long, and you can’t just put it in a drawer somewhere and have it stay charged.
In the case of a UPS, capacitors can readily supply a few minutes’ worth of power, and they are actually more reliable than batteries for this type of work.
Batteries, as you know, are designed to store electricity for long periods of time.
Many batteries are rechargeable, so you can use them multiple times, but there is one thing a lot of people misunderstand about batteries.
Every time you charge one, you cause chemical damage to the battery.
That means that every battery will ultimately wear itself out just by the nature of how it works.
Capacitors, on the other hand, are not chemically damaged through use.
Because of this, a capacitor can stay reliable for decades while most batteries need to be replaced every three years or so, depending on design and usage.
Can You Use a Home Inverter as a UPS? (3 Considerations)
We’re covering a lot of ground, and now we can get into comparing a UPS to a home inverter.
The first thing I want to explain is that most home inverters use batteries instead of capacitors.
Because of that, you need to check the battery health every six months or so, and eventually, you’ll have to replace the inverter’s battery (or the inverter itself if the battery isn’t replaceable), whether you lose power or not.
As long as you’re willing to face that potential maintenance issue, then many home inverters actually can be used as a UPS.
Let’s get into how that works.
#1 UPS Mode
Some home inverters are designed specifically to work as UPS devices.
In such a case, they usually have a UPS mode.
You can select that, and then the home inverter really does work just like a UPS.
The battery issue is in play, but it’s easy to stay ahead of battery degradation as long as you remember to check it every once in a while.
If you have this type of home inverter, there’s really not much else to it.
Plug it in and follow the instructions to get it into UPS mode.
The device takes care of the rest.
#2 Matching AC Frequencies
If your inverter doesn’t have a UPS mode, there’s still a good chance that it can work as a UPS.
After all, home inverters are designed to power home appliances.
Now, you might be worried about your computer receiving AC current from the inverter, but that’s not a problem.
Computers are already designed to deal with AC currents when plugged directly into a wall outlet.
They actually prefer to get AC power because AC to DC conversion is already built into the computer system.
AC power isn’t the problem in most cases, but there is one thing to know.
AC currents operate at different frequencies around the world.
Remember how I said that AC currents oscillate?
Well, the rate of oscillation is standardized by each country around the world.
In most cases, the AC standard will either be 50 Hz (in Europe and most of Africa, Asia, and Oceania) or 60 Hz (in the Americas, Japan, and South Korea).
What you need to know is that these frequencies are not cross-compatible.
You can’t use a 60 Hz home inverter in a 50 Hz country unless you have a special adapter and vice versa.
#3 Switching Time
Additionally, there’s an issue of switching time.
Home inverters are designed to go from passively sitting around to actively supplying power in the event of an outage.
The time it takes to make that transition is known as the switching time.
Computers are very sensitive to power losses, and even a short outage can cause your computer to shut off.
For the most part, computers need a UPS with a switching time of five milliseconds or less.
So, you need to check the switching time on your inverter.
If it’s 5 milliseconds or less time, then you’re good to go.
If the switching time is higher, then it’s not a reliable UPS for computers.