Joules, sine waves, and the fact that surge protectors wear out silently.
Verdict
A surge protector clamps voltage spikes. A UPS does that and adds a battery, so the computer keeps running through a cut and can shut down cleanly. If your work is on a desktop with no battery, or you run a NAS, a UPS is the one that prevents actual data loss. A surge strip alone does nothing when the power simply stops.
These are often shelved together and they do different jobs. One protects against too much voltage arriving; the other protects against voltage stopping.
~$19
Check Amazon Basics 12-Outlet Surge Protector, 4000 Joules Price~$190
Check APC BX1500M UPS 1500VA with AVR Price| Amazon Basics 12-Outlet Surge Protector, 4000 Joules | APC BX1500M UPS 1500VA with AVR | |
|---|---|---|
| Absorbs voltage spikes | Yes | Yes |
| Keeps running through an outage | No | Yes, for minutes |
| Corrects brownouts and sags | No | Yes, with AVR |
| Allows a clean shutdown | No | Yes, with software |
| Wears out over time | Yes, silently | Battery needs replacing |
| Cost | Low | High |
You want basic protection for peripherals, a television, or a laptop that already has its own battery. A surge strip with a decent joule rating absorbs spikes from the mains and gives you outlets. It is cheap enough that everything valuable on a desk should be behind one. Understand that the protection is consumable. The components inside absorb energy and degrade with each event, and most strips give no clear indication when they have stopped protecting, so a strip that has been in service for many years or through a known surge should be replaced. A strip with no surge rating printed on it is an extension lead, not a protector.
Check Amazon Basics 12-Outlet Surge Protector, 4000 Joules on Amazon
You run a desktop, a NAS, or anything that loses work when the power stops. A UPS holds the system up for a few minutes, which is enough to save and shut down properly, and its software can do that automatically if you are not there. Models with automatic voltage regulation also correct sags and brownouts, which are more common than outright cuts and which cause reboots. Two practical points. The battery is a consumable, typically lasting a few years, and a UPS with a dead battery is only a surge strip. And some equipment with active power factor correction, which includes many modern PC power supplies, works better with a pure sine wave model than with a stepped approximation, so check that before buying at the cheaper end.
Check APC BX1500M UPS 1500VA with AVR on Amazon
Neither protects against a direct lightning strike, and no consumer device does. During a severe storm the only reliable protection is unplugging equipment from mains and from any wired network or aerial connection, because a surge can arrive down a data line as easily as down a power cord. Also note that a surge protector needs a proper earth connection to work as intended; on ungrounded wiring, a strip's protection indicator may light while doing very little. If your outlets are old or you are unsure whether they are earthed, that is a question for an electrician.
Higher is better because the rating is roughly how much total energy the protector can absorb over its life. Something in the low thousands is reasonable for a desk. Treat it as a lifespan figure rather than a threshold: every surge consumes some of it, and once exhausted the strip usually continues passing power without protecting.
Usually minutes rather than hours, and that is the intended design. The point is to survive short cuts and to allow a clean shutdown, not to keep working through a long outage. Runtime depends heavily on load, so a desktop with a large graphics card drains it far faster than a router and a NAS.
If your equipment uses an active power factor corrected power supply, which many modern desktops and some appliances do, a stepped approximation can cause the supply to shut down or behave oddly when switching to battery. Check your power supply and buy accordingly. For routers, NAS units and older equipment, a simulated sine wave is usually fine.
Surge protectors should be replaced after a known large surge and after several years of service, since the protection degrades invisibly. UPS batteries typically need replacing every three to five years, and most units will report a failed self test when the battery is spent. A UPS that has never had a battery change and is more than five years old should be tested.
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these units side by side. Confirm current prices and specifications before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.