LMC Tech
Problem solved
The surge that kills your computer usually arrives when the power comes back on.
What a surge protector actually does, why a UPS is not just for servers, and which one you need.
The problem
Three different problems people lump together
The power flickered, and now the desktop will not boot, or the router has developed a personality. Or you simply lost an hour of unsaved work.
- Surges and spikes: brief voltage jumps, often when supply is restored after a cut, or from nearby lightning. This is what damages hardware.
- Cuts: the power simply stops. Nothing is damaged as such, but anything mid-write can corrupt, and unsaved work goes.
- Brownouts: voltage sags rather than stopping. Power supplies work harder and hotter, and it shortens their life quietly over years.
- A cheap surge-protected extension lead handles the first, poorly and only for a while. The protective components degrade with every surge absorbed, and there is usually no indicator telling you it has stopped protecting anything.
- Worth remembering from our broadband guide: in a power cut your router dies too, even though the line outside is fine. A UPS on the router keeps you online through a short cut.
The fix
What to actually buy
Cheapest and most effective first. A surprising amount of this costs nothing at all, which is not what most sites selling you things will tell you.
- Everything gets a surge-protected strip with a status light, replaced every few years. Cheap insurance.
- Desktops get a UPS. Not for hours of runtime, just enough to save and shut down properly. Laptops have their own battery, so they need this far less.
- Routers and NAS boxes are the underrated candidates. A NAS losing power mid-write can corrupt an array, and a UPS on the router keeps you online through the brief cuts that are most common.
- Size it simply: add up the wattage of what you are plugging in and buy a UPS rated comfortably above it. Do not plug a laser printer into a UPS, they draw huge startup current.
- Line-interactive is the sensible type for home and small office. Standby is cheaper and slower to react; online is for server rooms.
- Connect the USB cable so the computer can shut itself down gracefully when the battery runs low. Half of people never plug this in.
Refurbished
Refurbished UPS units come with a catch
Buying used is often the best value in tech, and occasionally a terrible idea. Which one it is depends entirely on the category.
Amazon Resale store- The electronics last well and the batteries do not. A used UPS is often sold with a battery near the end of its life, which is the one part that matters.
- That said, replacement batteries are a standard part and usually cheap, so a good used unit plus a new battery can be sound value. Just budget for the battery from the start rather than discovering it later.
Honesty note
How to actually find refurbished stock.
Worth knowing, because it is not obvious and we checked: you cannot filter an Amazon search to refurbished items from a link. We tried every documented approach and each one quietly returned ordinary new products instead.
The used and refurbished offers live on the individual product page, under the buying box, as "Other sellers" or "Used" options. Find the item you want first, then look there. The Amazon Resale storefront above is the other way in.
Who is telling you this
We fix this sort of thing for a living.
LMC Tech builds websites, software platforms and AI-readiness work, and supports the technology behind them. These pages exist because we answer the same questions repeatedly, and writing them down is quicker than repeating ourselves.
- Our work and portfolio, including Time Out Recovery, Echo Moon Western and LODORi.
- Web and software development: Django platforms and custom builds.
- IT support: the day job behind these opinions.
- Broadband backup guide.
- All the problems we have written up.
Rather not do it yourself?
We can just sort it.
Across Lincolnshire and remotely. If you would rather someone specified it, fitted it and made sure it works, that is the day job.