Unplug laptop while it is running

Am I "hurting" my HP laptop by leaving it running, unplugging from outlet - walking a few feet and plugging it back in? My brother-in-law says I am.

Donna

Posted 2016-05-09T00:04:56.157

Reputation: 531

80No, this is common practice. – Moab – 2016-05-09T00:05:44.850

8There is a minuscule chance of damaging the power supply, just as there is every time you go through a power cycle. There is a lot more chance of damaging the laptop by dropping it than by changing the power outlets. – AFH – 2016-05-09T00:24:58.863

@AFH - no kidding - when I consider how many people I see wandering around my office building - going floor to floor via elevators or stairs - while holding their laptop to their chest while it's open - I just wonder how many cracked screens the company is paying for. (Don't these guys have laptops that sleep?) – davidbak – 2016-05-09T16:15:42.740

12@davidbak I think that's the problem: they do not wish their computer to sleep (on some platforms, recovering from sleep is noticeably slower than not recovering from sleep, it interrupts wifi, or forces a lock screen [potentially requiring a domain controller to authorize the unlock]). Since the laptop sleeps, by default, every time they close the lid, they don't close it. Of course one can adjust the power setting, but that isn't known to all laptop users. – Calchas – 2016-05-09T16:24:04.537

3Yes, if you're not on battery! (e.g. data corruption) – Andrew T. – 2016-05-10T03:55:34.577

Yep there is no probleme with this practice – David 'mArm' Ansermot – 2016-05-10T11:17:19.703

Omitting the debatable memory effect I remember the problem of the membrane deterioration. It can be slightly accelerated by each inversion in the ions flux direction. When you pass from the charge phase to the discharge one, ions change the direction they pass through the membrane. Many inversions increase the hole sizes and their number. This accelerates the discharge rate of the battery, from inside, and increases the charging time (because it is discharging in the same time)... It should be nice to post updated references...

– Hastur – 2016-05-10T17:38:09.323

@Moab To be common does not make a practice good, not necessarily. :-). Nothing personal, just I've seen too many times common behaviours dictated by ease, indifference, laziness, momentary convenience, lack of knowledge or simply imitation... – Hastur – 2016-05-10T18:01:53.673

It is so normal behavior, that if you would do this and your laptop had a problem after that, it would be enough reason for a free repair / replacement in the warranty period. – peterh - Reinstate Monica – 2016-05-11T01:54:07.680

I think a good question is if there's a difference between the computer being asleep or not. What if it's busy writing to the hard disk at the very moment you plug it in? Will there be a power spike that can affect things? – Mr Lister – 2016-05-11T06:49:09.907

@Donna I know someone practically always asks this question and it can get annoying, but why do you want to do this? We might help you find a better solution to the deeper problem (if there is one) if we know. I doubt there is a deeper pertinent problem, but just in case, I thought I'd ask. – Brōtsyorfuzthrāx – 2016-05-11T08:09:39.227

Answers

Nope, it should be fine. Laptops are designed to switch between battery and mains power.

Stuff to watch out for? Tripping hazards. While barrel connectors are fairly robust, they've been known to fail — especially with a sideways force. Unplugging the power connector totally would mitigate both this and tripping risk. While there are special mechanisms for laptop HDDs that park the head, this is in case you drop it.

In essence, anything that can kill a laptop while moving it would kill it anyway. I've had a few desktop divas experience the same failure modes, so... it's not especially dangerous to move a laptop.

Journeyman Geek

Posted 2016-05-09T00:04:56.157

Reputation: 119 122

2+1 I've busted 2 laptop power... ports? holes? whatever the term is... by dropping it sideways and it landing on the plugged in cord. In the same vein as tripped hazards, make sure you have a good grip on it; dropping has a very similar effect. – jpmc26 – 2016-05-10T00:10:37.877

6I'd really move a laptop after unplugging everything. I'm a klutz – Journeyman Geek – 2016-05-10T00:41:47.533

1"I've busted 2 laptop power... ports? holes? whatever the term is" DC jack is the proper term :-) – Moab – 2016-05-10T01:23:08.577

I've had both sides break on different systems. I've also gotten into massive amounts of pedantry with 'sockets' 'jacks' and so on. Connector seems reasonably gender neutral. – Journeyman Geek – 2016-05-10T01:27:16.377

Much care should be taken when handling a device with a running hard drive as it can hurt it. Moving a running laptop with a hard drive is a bad idea. – Julie Pelletier – 2016-05-27T06:12:10.657

Your brother-in-law has an outdated view of how rechargeable batteries work. Older laptops used NiCd batteries were susceptible to the memory effect. Their maximum charge could be reduced if they were repeatedly partially discharged and then charged. There were all sorts of attempts to mitigate this, including waiting until the battery was discharged before charging it again. It's debatable whether the memory effect was real.

Modern laptops use lithium-ion batteries which have no such problem. They also have sophisticated hardware and software to monitor the battery, keep it in good condition, and prevent anything a consumer is likely to do from harming it.

Schwern

Posted 2016-05-09T00:04:56.157

Reputation: 1 978

1Maaaan. I don't remember the last time I saw a NiCd powered laptop. Late 90s? – Journeyman Geek – 2016-05-10T06:51:46.840

There is not only the "debatable memory effect" but even the membrane deterioration one (eventually see above the comment to the question). Technique makes progresses and materials changes each day, but I shouldn't be so strict judging the brother-in-law, even if they always get wrong, by definition :-). – Hastur – 2016-05-10T18:09:34.337

2For what it's worth, the old NiCd packs had such horrible problems with memory effects because the manufacturers were cheapskates. The packs were designed for the computer to work while each cell was in the 1.2-1.5v range. For NiCd batteries this is the "overcharge" zone and holds relatively little power. The vast majority of the cell's power storage is in the 1.2-1.0v range. I rebuilt a few packs and added one more cell so the pack was operating in its main range instead of overcharge and the run-time tripled, as well as being able to properly discharge the cells to avoid memory problems. – Perkins – 2016-05-10T18:58:30.893

I don't see any indication in OP's question that this is the source of the BIL's cluelessness. – R.. GitHub STOP HELPING ICE – 2016-05-10T22:16:15.610

1@R.. Sure, the brother-in-law could think it will spook the electricity ponies that make the laptop go. I'm making an educated guess based on the rationale behind questionable advice I've heard about laptops over the last two decades. – Schwern – 2016-05-10T22:21:45.940

@JourneymanGeek NiCd?! Luxury! I remember the old mac portable that had a lead battery the size of something you'd pull out of a motorcycle. Mind you, if you did roast the battery in those days you could just pull out a set of jumper cables and bring the car around to give the laptop a boost. 0_o – J... – 2016-05-11T02:45:51.480

Dropping a lithium ion battery on the other hand, can reduce its charging capacity. – Brōtsyorfuzthrāx – 2016-05-11T08:15:39.053

Unless your laptop doesn't have a battery, you're fine. Leaving it plugged in all day, everyday can minutely reduce your battery's efficiency. But since your battery degrades overtime anyway, that's not really an issue. Lithium batteries don't last forever, nor retain their peak efficiency indefinitely.

NonCreature0714

Posted 2016-05-09T00:04:56.157

Reputation: 237

11The control circuit for a Lithium Ion battery is such that leaving it plugged in is unlikely to noticeably degrade your device. I'd be more concerned about a fire from overcharging, if the circuit failed. – Gusdor – 2016-05-09T13:26:32.830

7@Gusdor I think this has become conventional wisdom because it was much more likely to be true of Nickel-Cadmium batteries. – Random832 – 2016-05-09T14:22:55.543

1Ah, true - she didn't specify whether she had a lithium or nickel cadmium battery. Or how recent her laptop is. The answer would change based on her laptop model, but still be mostly ok. – NonCreature0714 – 2016-05-09T14:31:09.850

@Random832 good shout. I wasn't aware of the distinction. – Gusdor – 2016-05-09T14:32:14.607

4@Gusdor two of the many, many things that shorten the life of a Li-ion are being kept at full charge (for example because a laptop is keeping it topped off) and being kept at high temperature (for example because it's stuck inside a running laptop). It's a really sensitive chemistry. – hobbs – 2016-05-09T15:06:57.763

For more info about prolonging your Li-ion battery: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

– Wayne Werner – 2016-05-09T18:25:56.577

LOL - The statement was both something I've actually seen – a network security person I once knew refused to keep a battery in their laptop, and ran kali linux from a disc (the person also replaced subcomponents daily, super paranoid) – and was an amusing illustration which was called to my mind because of it. No harm meant, but certainly a little humor. :) – NonCreature0714 – 2016-05-10T05:05:53.237

@NathanOsman Consumer laptop batteries usually don't last very long: 2 years, maybe 3. And when they are worn the laptop keeps recharging them continuously with eats a lot of power (without much benefit) and produces a lot of heat (which keeps the noisy fan going continuously and make using the laptop unpleasant). Buying a replacement battery usually doesn't make sense. Expensive and in some cases impossible (model gone out of production). In that case taking the battery out and running the laptop only from the mains starts looking attractive. – Tonny – 2016-05-10T15:07:38.310

1@Tonny As someone who is currently replacing the battery in their still otherwise fine 2011 laptop, I must disagree. – Schwern – 2016-05-10T22:34:35.520

@Schwern I said usually, didn't I ? I've got a 2006 laptop myself for which I bought a new battery in 2012. In my case it did make sense as this laptop has a matte 1600x1200 screen (15.6", they don't make those anymore) and, with Linux, still has enough performance for my usage. At €90,- the battery was reasonably priced. – Tonny – 2016-05-11T10:53:29.183

Yes you are but not in the way you think. Unplugging it and replugging is fine however hard drives are not designed to be moved while in use and are extremely fragile and easily damaged by bumps that would be safe while the laptop is not in operation.

JamesRyan

Posted 2016-05-09T00:04:56.157

Reputation: 1 591

4Many modern laptops have an SSD today, which is not susceptible to heads crashing due to vibration or movement. – dotancohen – 2016-05-10T11:37:15.087

3@dotancohen Surprisingly enough SSDs in laptops are still quite rare, in all but the higher end, because of the added cost. But what you say is right if it has one. – JamesRyan – 2016-05-10T11:47:52.570

8Most every laptop I've seen in the past 10 years or so also has acceleration sensors and driver-level software to turn off spinning disks to prevent damage to the hard drive in the event of acceleration that would crash the disk heads, so this isn't likely to be an issue. – HopelessN00b – 2016-05-10T14:07:44.473

Modern spinning disk hard drives, especially 2.5", are not "extremely fragile". Laptops are designed to be moved while in use, otherwise they'd just be a portable desktop Their drives will not be easily damaged by a bump. Just don't drop your laptop, but even that isn't so bad anymore.

– Schwern – 2016-05-10T22:31:54.130

1@Schwern "Laptops are designed to be moved while in use" no they are not. Look at your manual, all the main manufacturers currently advise against it. Active shock protection only works against a fall, it does not work against bumping it on a desk or the gyroscopic forces of tilting it. Laptop drives can withstand many G shocks while the heads are parked but not while the heads are active. – JamesRyan – 2016-05-10T23:22:45.667

@JamesRyan I'm pretty sure Apple will not void my warranty because I walk around with my Macbook open. Every hard drive has a shock (in g's over time) and vibration (in Hz and g's) tolerance while operating and not operating. For example, this Toshiba drive can handle 70g's over 2ms and 5-500 Hz of vibration at 0.5g's while operating. The specs for the Seagate Barracuda are similar.

– Schwern – 2016-05-10T23:43:24.303

1@Schwern sounds impressive until you consider that a laptop dropped from 10cm onto a ceramic floor experiences more than 300G over 2ms. Plonking a laptop heavily onto a desk can easily go above 70G and will not always activate the shock protection. So moving around a laptop is only fine when you treat it as fragile and put it down gently. The drive records the max shock it has been exposed to in operation so yes Apple will void your warranty when they can see damage caused by shock. – JamesRyan – 2016-05-11T11:36:21.740

I regularly am stuck with a long winded operations in Windows and Linux, and therefore move the laptop while in use, even with running and or copying to/from USB drives. No problem yet. On the other hand a small move of an internal harddrive (not attached with screws) while using dd on Linux resulted in a bricking of the (old, second hand) drive. Probably the age was partly at fault. – vinnief – 2016-05-24T05:46:46.147