UPS Battery Backup – Comprehensive Guide and Top Picks

With a UPS, you’ll never have to worry about short blackouts and power surges ever again!

Who hasn’t suffered from an untimely power outage, which causes the PC to shut down abruptly and wipes out several hours of work? Or a micro outage, which leads to an internet disconnection in the middle of an online game? Fortunately, there is a solution to avoid these inconveniences: the UPS.

Thanks to the battery it carries, a UPS acts as a backup power supply that will provide several minutes of autonomy to your electrical devices. Thus, you will have time to finish your tasks in progress, save your documents and shut down your computer properly in case of power failure. In addition, this device also acts as a power strip surge protector that offers effective protection against the risk of power surges.

Things to Keep in Mind When Selecting Your UPS Battery Backup

A UPS is usually used to protect computer equipment (desktop PCs, network hard drives or internet boxes), but it can also be used for other types of electronic devices. Moreover, such a protection device is particularly useful for a video projector, whose lamp is very sensitive to the thermal shock caused by the absence of cooling by fan following a power cut. However, depending on the intended use, different criteria must be considered.

⚡ How much power do I need?

There are many models with power ranging from 400 to over 3000 volt-amperes (VA)! What is the difference with watts (W), usually used to express electrical power? Well, the watt corresponds to the real power while the voltampere corresponds to the apparent power. This apparent power is the maximum power that can be supplied by an electrical source such as a PC UPS, or even your electrical meter. It is equal to the real power divided by a coefficient called the power factor (PF). In other words, the apparent power in VA is always higher than the real power in W. For example, the data sheet of the Eaton 3S 700 VA indicates a power of 420 W.

It is imperative that your UPS has a sufficiently high real power to ensure the supply of the equipment you wish to connect to it. To evaluate the power required for your needs, you can for example refer to these indications of electrical consumption:

  • 2-bay NAS: ≈ 20 W
  • TV LED 55″: ≈ 100 W
  • Playstation 5: < 200 W
  • Central unit for office use: < 100 W
  • Internet box: ≈ 10 W
  • PC monitor up to 32″: < 50 W
  • Inkjet printer: ≈ 25 W
  • Gamer PC central unit: between 250 and 500 W

Thus, a 550 VA (≈ 300 W) device is more than enough for a NAS, a gaming console and TV, or a desktop PC and its monitor. On the other hand, it will be a bit short to support the needs of a PC designed to run very demanding 3D games. In this case, we recommend a 500W or higher model as a gamer PC UPS.

The best UPS for PC gamers…

UPS battery backup for pc… must above all be able to deliver a power adapted to the gamer’s configuration! A gamer PC is more powerful than a computer designed for office and multimedia use, and this translates into a much higher power consumption, especially when you are in the middle of a game. So you need to make sure you have an adequate PC UPS. Especially since it must be able to deliver enough power on a daily basis and not only when a power outage occurs. Indeed, a device that requires too much power will light up an overload indicator, and often emit a strident beep, to warn that its capacity has been exceeded.

But then, how much power does a gaming PC consume under load, when its processor and graphics card are heavily used? Well, an entry-level tower with a quad-core processor and a GPU such as a GeForce GTX1660 or an older GTX970 doesn’t exceed 300W when gaming. But this is already much more than using it only for surfing the net, which will not require more than 60 to 90 W! With a mid-range graphics card like GTX 1070, RTX 3060 Ti or Radeon RX 5700, it is better to count 400 W under load. Finally, with a powerful configuration to play in 4K, embodying a hexacore or even octocore CPU and a graphics card such as a GeForce RTX 3080, it is the 500 W mark that is reached. And that’s just for the CPU! If you add, at the very least, a screen that can consume up to 50 W, you can see that you need to opt for a really strong PC UPS!

If you have a relatively modestly powerful machine, you should therefore opt for a model that delivers around 500 W, like the Eaton 3S 850 FR. But if you want to be more cautious, or for the most demanding high-end PCs, the APC Back-UPS BX1400U-FR is the one to choose with its 700 W.
🔋 How much autonomy will I have?

From one model to another, there are big differences in autonomy. This depends of course on the power of your devices, but it is also conditioned by the size of the integrated battery. The capacity of the battery, which is expressed in mAh, is rarely communicated. It is important to note that UPS systems are not designed to power the devices they protect for long periods of time. A desktop computer can usually run on battery backup for 10 to 30 minutes, rarely more, even with the best PC UPS. This is enough time to save your documents or games and then shut down the machine properly in the event of a prolonged power outage. And the models we recommend in our selection can be connected to your computer which, by means of a software (supplied), will then be able to turn itself off in the event of a power cut once the batteries are almost drained!

💡 What is the difference between off-line, in-line, and on-line models?

There are 3 types of UPS on the market. Most consumer models are said to be off-line (or standby). When a voltage drop is detected, the device switches to the emergency circuit, the battery circuit. This operation, which can be guessed by the click of a relay, takes up to 6 ms. And if usually PCs don’t have time to crash or reboot that fast, it can happen exceptionally. Moreover, an off-line model does not offer any regulation to smooth out small variations in electrical voltage.

A little more expensive, the in-line UPS (or line interactive) are a little more sophisticated. Their overall operation is the same, but the switching from the main circuit to the backup circuit is controlled by a microprocessor which saves time (maximum 2 ms to switch to battery in case of a power cut), further reducing the risk of crashing. Moreover, the input voltage is permanently controlled, which allows a regulation of the output voltage. This automatic regulation is done without stressing the battery, which preserves its life.

Finally, even if they are only found in server rooms or associated with critical professional equipment that absolutely must be protected, you should know that there are models called on-line. This means that, unlike the others, the batteries are in series and the current flows through them permanently. In other words, there is no switching and therefore no risk of crashing at that moment. In addition, as with in-line technology, the voltage is regulated and therefore very stable. On the other hand, the battery of an on-line model wears out more quickly. Moreover, an on-line UPS is always rather noisy, unlike off-line or in-line devices, which are generally very quiet. This is due to the fact that in the case of on-line models, the batteries are constantly in use, and not only when there is a problem with the mains.

2021‘s Top 4 Uninterruptible Power Supplies

Eaton 3S 550 FR Gen2Eaton 3S 850 FR Gen2APC Back-UPS ES BE850G2APC Back-UPS BX1400U
Picture Protection électrique - Onduleur Eaton 3S à 6 connecteurs Protection Station 850 VA pour usage domestique Onduleur APC 850 VA - Prise parafoudre et régulateur automatique de tension Meilleur onduleur pc gamer - APC BACK-UPS BX 1400 VA
Output Power Capacity 550 VA / 330 W 850 VA / 510 W 850 VA / 520 W 1400 VA / 700 W
Battery Runtime
50 W : 33 min
300 W : 4 min
Full Load (330 W) : 3 min
50 W : 69 min
300 W : 7 min
Full Load (510 W) : 1 min
50 W : 72 min
300 W : 8 min
Full Load (520 W) : 2 min
50 W : 105 min
300 W : 14 min
Full Load (700 W) : 2 min
Type Off-line Off-line Off-line In-line
No. of Battery and Surge Protected Outlets 3 4 6 4
No. of Surge Only Outlets 3 4 2
Surge Protection
USB Charging Port
(Type-A + Type-C)
Data Line Protection
Management of the UPS via a USB
Dimensions 325 x 140 x 86 mm 335 x 170 x 84 mm 365 x 130 x 120 mm 336 x 215 x 130 mm
Weight 3,2 kg 4,0 kg 4,5 kg 12 kg
Warranty 2 years 2 years 3 years 2 years

Eaton 3S 550 FR

Uninterruptible power supplies - Eaton 3S 550 VA

The Eaton 3S 550 FR is a perfectly silent device, which sets it apart from some of the discount models that can be found in the competition. It has 6 outlets with lightning protection, 3 of which are battery operated to avoid any data loss. Capable of delivering a power of 550 VA, or about 330 W, this model is ideal for protecting a PC whose main uses are office, Internet and multimedia, as well as its main peripherals (LCD screen, speakers, etc.). But the Eaton 550 FR will also find its place perfectly in the living room to protect the TV, the game console and the home cinema audio system (and all at once!).

For use limited to equipment with modest power consumption, some might be tempted to go for the Eaton 450 FR, which as its name suggests is capable of delivering 450 VA (270 W), and requires a lower investment. However, we prefer the 550 FR model, because unlike the 450 FR, it can be connected via a standard USB plug to the computer’s mainframe (but also to a Synology NAS) to benefit from software control. It offers very useful functions such as viewing the battery status, programming the shutdown of a device in case of a prolonged power failure or configuring email alerts.

The Eaton 3S 550 FR has an on/off switch that prevents the devices connected to it from consuming unnecessary energy when they are on standby, even if you leave it connected to the electrical system. And as always with the 3S range, if needed, the battery can be replaced in a minute without any tools. The on-board model is fairly common, easy to find and inexpensive.

Eaton 3S 850 FR

Uninterruptible power supply Eaton 850 VA

The Eaton 3S 850 FR is the big brother of the 550 FR we talked about before, so it shares many of the same strengths: it is just as quiet, convenient, and space-saving, it allows for software control, and its battery is very easily replaceable.

It stands out mainly because of its power, which can reach up to 850 VA and which positions it as the most powerful model in the 3S range. These 850 VA give a real power of 510 W: it’s enough to protect against lightning and power outages a quite powerful gaming PC, as well as a screen (maximum 32″). Still, keep in mind that as with all UPS, when the output load approaches the maximum power, the autonomy will not exceed a handful of minutes. Thus, we have 3 minutes of autonomy at 450 W, then we go down to 2 minutes at 480 W to reach 1 minute at 510 W. This is far from a generator, but it is enough to give you time to record your game or save your work data and then turn off the PC in case of a power failure.

Compared to the 550 FR, this 850 VA version is equipped with a richer connectivity, since in addition to the 2 additional electrical outlets, it gains RJ outlets to protect your ADSL/VDSL Internet box from a surge that would arrive through the telephone network. In addition, there are 2 USB sockets that deliver up to 2A to charge your mobile devices.

With its advanced features and unbeatable price/performance ratio, the Eaton 3S 850 FR is probably the best PC UPS on the market.


Best ups battery backup - APC ES 850 VA

APC Back-UPS have been setting the standard for decades now! The ES series models are relatively compact and look like large power strips. With a real power output of 520W, the APC Back-UPS ES BE850G2-FR is the perfect choice for connecting a gamer PC with one or two monitors. And thanks to the absence of a fan, this unit is completely silent. Only a slight humming sound is heard in case of a power failure, when the system switches to battery power (this is the case with all UPSs).

With the 6 battery-powered outlets offered by the APC Back-UPS ES BE850G2-EN, you can easily connect other devices such as an Internet box in addition to the PC and its screen. This means you can send an emergency e-mail or notify your contacts on messenger in the event of a power cut! In addition, if you keep the BE850G2-FR on your desk, you can also take advantage of its USB charger that offers both a type-A and type-C plug.

All Back-UPS series models can be connected to a PC via a USB cable (for the BE850G2-EN, this cable is provided free of charge upon request from APC), and programmed by the PowerChute Personal Edition software. This software provides a lot of useful information such as the power consumption of your PC, the input voltage or the battery status. But even without this, Windows natively displays an estimate of the remaining autonomy, and moreover, a light on the UPS as well as an audible alarm allow to quickly identify the battery status (low, discharged or defective). Practical! As a bonus, this 850 VA model is guaranteed for 1 year more than the legal 2-year warranty, i.e. 3 years.


UPS battery backup - APC BX 1400 VA

The APC Back-UPS BX1400U-FR is a more powerful in-line device. Unlike off-line models, in-line devices regulate the input voltage before delivering it to the connected devices, without straining the battery, thus increasing its life. In-line UPS are recommended in rural areas, where electrical disturbances are more frequent. Although its size and appearance are reminiscent of professional UPS designs (often noisy), the BX1400U-FR does not require a fan. Thus, it is perfectly silent.

With 1400 VA, that is to say 700W, this device is powerful enough to guarantee a well-muscled PC and its peripherals an uninterrupted operation in case of short power failures. As always, the autonomy will depend on the output power. Count on 1h45 for 50W, which is enough for a NAS and the ethernet box for example. With a PC in office use, which would consume 150 W, we go down to 34 minutes of autonomy. For a Gamer PC running at full speed, we go from 9 minutes for 400 W, to only 2 minutes for 700 W. Anyway, you can see the remaining autonomy under Windows, provided that you have connected the UPS to the PC via USB.

Unlike the BE850G2-FR, the BX1400U-FR does not have a USB charger and it has only 4 plugs on battery. To have 6, you must opt for the version with IEC plugs (reference BX1400UI). But beware, these plugs are only usable for CPUs, screens, and rare peripherals (some printer, NAS or scanner models). And to use them, you need male/female IEC extension cords. In our opinion, it’s better to stick with the model equipped with standard electrical outlets to facilitate your connections.

What is the average lifespan of UPS batteries?

UPS use lead-acid batteries, like our cars, but much smaller. And, like all other batteries, they do not last forever; the chemical processes involved in the charge and discharge cycles cause irreparable wear and tear over time. The batteries of the models we have selected are guaranteed for 2 to 3 years but, fortunately, they generally last longer. Their capacity generally remains satisfactory for 4 to 5 years. Beyond that, it's more a matter of luck than anything else, even if some batteries still perform well after 7 years. Most devices allow for battery replacement to extend their life, and this is the case with the models we recommend.