There are simple power strips and power strips with surge protection (and also with short circuit protection). Is there difference in that matter for PCs and laptops? If I use laptop I have a battery (does this protects me from such stuff) and a power adapter on the power cord. May be the adapter does something, doesn't it?

2 Answers 2


Short answer: Yes

For laptops and mobile electronics, I always recommend surge protectors that use resettable circuit breakers, such as Panamax's Power360 Wall Tap (auto-senses under-voltage and over-voltage, auto tripping and resetting its internal breaker when required, providing a LED ring with three diagnostic lights).

  • Using any externally powered electronics without a surge protector risks permanently damaging those electronics when a surge occurs (it's not a matter of if, but when)

A battery is simply there to power the device, not absorb fluctuations in voltage and amperage the way a vehicle's battery does; small fluctuations are dealt with via the AC-to-DC power adapter/brick.

  • Lithium-based batteries require a very specific charging voltage and amperage range - they are not there to absorb a voltage/amperage surge, as doing so could have serious repercussions from heat damage
    • If the battery temp rises high enough from over-voltage/current, it can melt it's hermetically sealed electrolyte which burns explosively when exposed to oxygen

A surge would likely only fry the laptop's power brick, but whether any of the excess voltage/current could pass to the laptop is dependent on the internal design of the power brick.
Surge protectors should be purchased based on Joule rating (higher Joule rating = better).

  • Surge protectors, excluding those with resettable circuit breakers, have a finite lifespan and can only be reliably used for a few years, usually two to three years is what most manufacturers guarantee.
  • Non-resettable circuit breaker protectors are one-time use only protection items - once a surge occurs, the surge protector needs to be replaced.
  • 1
    You still need a surge protector against fast and large surges. Circuit breakers have limited capability.
    – John
    Jun 24, 2020 at 0:17
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    @Rick To piggy back John's comment, electrical panel circuit breakers are there to protect the building's electrical wiring, not individual components (a whole home surge protector at the panel is recommended, but its purpose is to protect large appliances only). Circuit breakers don't trip as soon as the current exceeds the breaker's rating - it trips when enough heat has been generated to expand the bimetal contact (check out YouTube videos that show what happens internally with a breaker during a surge - it's not an instantaneous trip unless the current surge is significant).
    – JW0914
    Jun 24, 2020 at 3:55
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    @Rick Neither would be recommended, as that's too low of a rating since Joules are the amount of energy absorption/dissipation it can handle before the MOVs (surge protectors w/o a circuit breaker use MOVs) fail, passing that voltage/current onto plugged-in devices. ~1000J would be the minimum I would recommend, with the bare minimum I'd recommend being ~600J for small electronics like PCs, routers, printers, etc. EchoGear provides a basic explanation and recommendations, such as an absolute minimum of 400J.
    – JW0914
    Jun 26, 2020 at 14:02
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    @Rick Cont'd... MOVs (Metal Oxide Varistors) are what absorb excess voltage/current, which fail after x surge cycles or all at once w/ a large enough surge; it's for this reason surge protectors w/o resettable circuit breakers are recommended to be replaced every 2 - 3yrs. The "Protected" / "Protection" LED should be checked regularly, as it goes out when all MOVs have failed (surge protector will still power devices, but will have no surge protection). Even w/ circuit breakers, a low enough surge can still pass until it generates enough heat to fully flex the bimetal contact
    – JW0914
    Jun 26, 2020 at 14:07
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    @Rick I think you're referring to one of the lights on the Surge Protector? If so, that light will either have a label next to it, or you'll need to look up the manual/call the manufacturer to determine what that light is. If it's the Protection/Protected light that's no longer turning on, the surge protector should be replaced as its MOVs have all failed due to a surge or surge cycles and it will no longer protect against surges.
    – JW0914
    Jun 27, 2020 at 10:43

A laptop battery can protect against low level fluctuations and short term power outages and subsequent power restarts.

The AC input has a range of input voltages and the battery provides basic power to accomplish the above.

But that does not protect against a major power surge like a lightning strike. You still need a surge protector for such events.

We have (and have had) clean power here so I do not equip my laptop with a surge protector because the need does not exist (greater than 99%)

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