1 The actual difference
Power strip
Six outlets, zero protection
An extension cord that splits one outlet into several. Usually a circuit breaker for overload, and that's it. Roughly $8–$15.
Surge protector
Absorbs the spike for you
Same outlets, plus components that shunt excess voltage to ground before it reaches your gear. Roughly $25–$40.
Joules are the size of the tank. A joule rating is roughly how much surge energy the protector can soak up over its lifetime, in one hit or across hundreds of small ones. Higher is better and it’s the number worth comparing.
Clamping voltage is the trigger point. It’s the voltage at which the protector starts diverting power. Lower means it reacts sooner, so 400 volts or less is what you want.
Most surges aren’t lightning. They’re small spikes from your own house – the furnace, the well pump, the AC compressor kicking on – chipping away at electronics for years.
2 What goes in which
Surge protector
Desktop computers
Laptops and their chargers
TVs and sound bars
Game consoles
Modem, router, Wi-Fi gear
Printers
Anything with a screen or a circuit board you'd hate to replace
Power strip is fine
Lamps
Box fans
Phone and tablet chargers
Christmas lights
Shop tools you plug and unplug
Anything cheap you wouldn't mind replacing
Wall outlet only
Space heaters
Microwaves
Toaster ovens and air fryers
Refrigerators and freezers
Window air conditioners
Anything that makes heat or has a motor
High-draw appliances pull more current than a strip is built for, and that’s how strips melt. They go straight into the wall every time, no exceptions.
3 Reading the box in the store aisle
Four things on the package tell you almost everything. If a box doesn’t list them, that’s your answer.
Joule rating. Under 500 is barely worth it. 1,000–2,000 covers a TV or a laptop. 2,000+ for a desktop, a home office, or a whole entertainment center.
UL 1449. That’s the safety standard for surge suppression specifically. “UL listed” on its own only means the cord and outlets are safe; it says nothing about protection.
Clamping voltage of 400V or less, and a “protected” indicator light so you can tell later whether it’s still working.
A connected-equipment warranty. Mostly it’s a signal of confidence – claims mean paperwork and receipts – but a manufacturer willing to back the unit usually built a better one.
Surge protectors wear out…quietly
This is the part almost nobody knows. The protection inside is consumable. It absorbs spikes until it’s used up, and then the outlets keep working exactly as before – you just have an expensive power strip.
Check the “protected” light. If it’s off or amber while the power light is on, the protection is spent. Replace the unit.
Replace it after any big event: a close lightning strike, a hit from the power company, an outage that came back hard. One large surge can use up the whole tank.
Otherwise, plan on every 3–5 years. Write the date on the bottom in marker when you buy it. Nobody remembers otherwise.
5 What a surge protector won’t stop
A direct lightning strike. Nothing on a shelf stops that. In a bad storm, unplug what you care about; it’s still the only real protection.
Outages and brownouts. A surge protector only handles too much voltage, never too little. Dips and hard shutdowns are what corrupt drives and lose files; that’s a battery backup’s job.
Surges that come in on another wire. Coax and Ethernet carry spikes too. That’s a common path into a modem, and it’s why some protectors include coax pass-through jacks.
Bad wiring or a missing ground. Protectors dump excess voltage into the ground wire, so on an ungrounded two-prong circuit there’s nowhere for it to go. Older houses around here have plenty of those.
6 Battery backup: who actually needs one
A UPS (uninterruptible power supply) is a surge protector with a battery inside. When the power drops it keeps running for a few minutes, long enough to save your work and shut down properly. Small ones run about $80–$150.
Worth it for a desktop. Desktops have no battery, so every flicker is an unplanned shutdown. If your power blinks in storms, this is the fix.
Worth it if you work from home. Put the modem and router on it too and a brief outage doesn’t end your meeting.
Skip it for a laptop. It already has a battery. A good surge protector is enough.
Note that UPS batteries only last a few years. When it starts beeping constantly, the battery wants replacing, which is usually cheaper than the whole unit.
7 What we actually see on the bench
Dead power supplies after a storm. Sometimes that’s the whole repair and the rest of the machine is fine. Sometimes the spike went further in and took the motherboard with it.
Modems and routers that came back with no internet ports. Classic sign the surge arrived on the coax or phone line rather than the outlet.
Drives that won’t boot after an outage Not fried, just interrupted mid-write. Often recoverable, but it’s a bad afternoon and the reason we push battery backups for desktops.
Fifteen-year-old strips under desks, packed with dust, still holding a whole office. Even the ones that were surge protectors gave up on that job a decade ago.
Five rules for both kinds
However good the unit is, this is how it fails
Don’t daisy chain. One strip into another isn’t more outlets, it’s a fire risk.
Don’t plug one into an extension cord. Straight into a wall outlet, always.
Don’t overload it. Six outlets doesn’t mean six heavy things.
Keep it dry. Not on a damp basement floor, not near a sink.
Don’t cover it, and keep it clean. Not under a rug or behind a couch cushion. Dust is fuel; blow it out now and then.
Think a surge already got something?
Bring it in and we’ll tell you what survived and what didn’t. Most jobs are covered by our flat $100 bench fee, and we call before anything costs more. We don’t sell surge protectors, but we’re happy to tell you what to look for before you buy one.
