Although the electricity grid in our regions is reasonably stable, we have seen major power failures with some regularity in recent years, which often also last a long time. A UPS (Uninterrupted Power Supply) is not that bad after all to prevent data loss and possibly even damage to your valuable computer equipment.
Pats, suddenly it’s dark in the house. Electricity out. This can simply be due to a fuse that has blown out, or it is something from the outside. In the latter case, it can mean a failure of a few seconds or many hours. Whatever the cause, a switched on computer or NAS, for example, runs on electricity. If that fails, those devices will also switch off.
It is annoying that this is not done ‘cleanly’ via a closing command. In the worst case, this can lead to damage to system files and a system that no longer starts. Or a file in which you have spent many hours of work gets damaged. This applies to both your computer and a NAS that is running at home.
If you want to avoid the worst misery, a UPS is the savior. In this device you will find a battery that (in most cases) converts the energy stored therein to the mains voltage with which your computer or NAS normally works. Switching from a lost mains voltage to AC voltage supplied by the NAS itself is so fast that no computer notices anything. In short: no risk of file loss!
Connecting UPS, what do you need to know?
Now, a UPS is not a panacea either (unless you spend an extreme amount of money on it), and depending on the chosen capacity and the load that your computer or NAS forms, it is mainly intended to save time to turn off your computer properly. The running time on the battery in the UPS varies from anywhere to a few minutes to sometimes more than an hour and a half.
Furthermore, most UPSs have a USB connection that informs the computer or NAS that the system is running on emergency power. Either via the supplied tool that comes with the UPS or via a facility built into the system, you can set how long the computer or NAS can continue to run on the emergency power supply. Consider, for example, 30 seconds for a somewhat smaller-sized UPS.
Even better is setting a lower limit in terms of battery percentage of the UPS, for example 30%. Then you usually have more ‘working time’ left. After that, the system is neatly shut down, in a similar way to turning off your computer by clicking Switch off or something similar. Result: your (system) files are not at risk.
As soon as the mains voltage is back, you can switch everything back on and continue working. Don’t do that until you have given the UPS an hour or so to recharge its batteries, otherwise there will be no protection at all.
pure sine wave
In fact, you should mainly choose from UPSs that offer a ‘pure sine wave’ as the output signal of the alternating voltage. In other words: a neat sinusoidal signal that is not inferior to the equally beautiful sinus that normally comes out of you Wall outlet comes.
There are also cheap UPSs that present a so-called modified sine wave as an output signal. That can go well, but modern PC power supplies and the like can’t handle it well. There is a chance that when such a UPS switches to emergency power, your PC still fails because its power supply goes into error mode. Such a vaguely shaped output voltage can also cause unnecessary heat development.
If you do spend money, go for a UPS that supplies a pure sine wave as an output. Good news: this used to be a relatively expensive affair, but nowadays that is no longer the case. So why take the risk?
UPS power
Which power you should choose for your UPS is of course very dependent on the power of the connected devices and the length of time for which you want a device to run on UPS voltage. Keep in mind that the power of a UPS is almost always indicated in VA; the number of Watts depends on the type of load that is connected to an AC voltage.
In essence – with alternating voltage – the power in Watts is always lower than the power in VA. So if you have a constant load of 500 Watt on a UPS, then a UPS with a capacity of 600 VA is too little to make sense.
However, we are not there yet. No computer continuously consumes the power stated on the power supply of that device, often only a fraction of it. However, if the power goes out in the middle of a solid gaming session, the energy consumption is probably at its highest. In that case, it is important to close the game as soon as possible (if your system does not immediately start the shutdown procedure).
It is also useful to attach your screen and preferably also any connected backup USB drive to the UPS, for obvious reasons. This means that for the average to heavier PC you can’t go wrong with a UPS of, for example, 1000…1500 VA. For a single NAS you can get away with something like 600 VA, which gives a reasonable runtime on UPS power.
Compatibility
The UPS would like to notify the connected devices that it has switched to emergency power. In the case of appliances for home use and UPSs intended in principle for a single PC, this is arranged via USB. It makes sense – especially for Mac users – to buy a UPS that is HID compatible. Then you don’t have to install drivers and software. The same applies in most cases to Windows 10 (and higher).
A UPS that does not have HID compliant communication will also work, but you will need to install a driver and associated software. Which in turn causes extra hassle and possibly unnecessary obsolescence because a device in a newer version is suddenly no longer supported in terms of drivers. So go for HID, also the most ‘secure’ – in terms of compatibility – when it comes to a NAS.
DC Mini UPS
There are also mini-UPS for DC voltage. They look like a standard mains adapter, but internally a (usually sturdy) lithium battery is incorporated. If the mains voltage drops, the battery takes over. These things are ideal for connecting your router and a switch in strategic places. That way you can at least keep using the internet for a while!
Experience here shows that a Fritz!box runs for just under an hour on an adapter with a built-in 10 A/hour lithium battery.
Additional Features
If you go for a ‘large’ UPS, pay attention to the extras. Several models have over- and under-voltage protection (regulation) and some also have USB charging ports on board. You can also keep your smartphone, tablet, rechargeable flashlight and so on in the event of prolonged power failures.
In conclusion: Batteries in a UPS have a lifespan of three to five years. Before purchasing the intended UPS, check whether the batteries can (easily) be replaced by you as the end user. And actually do that after three or four years. Even if everything still seems perfectly fine!
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