How long can a laptop be left on and running?

If a laptop were on and running for a week, never being put into sleep mode, would it overheat or suffer significant wear and tear due to no rest?

As long as the cooling intake and exhaust are not obstructed I can’t think there’d be any problems. Make sure it’s not on a soft surface that would restrict airflow.

Is there a reason it can’t sleep? Will it wake if it receives external input?

I’ve run one as a “temporary” server for over eight months without letting it sleep (although I did allow a screen saver). And there’s an iMac not far from me that’s been running for years – not technically a laptop, but basically the same components.

No, it doesn’t wake up from external input.

As long as it is in a reasonable environment and has adequate ventilation directly around it, you can leave a laptop on indefinitely without any ill effect. I work in in industrial IT and some people that get laptops as their work computers just plop them into docking stations at their desk and never take them anywhere else. They can stay up for months or years at a time excluding reboots for maintenance or software updates. As far as I know, it has no known effect on their overall lifespan in general.

I have had one running for months on end. This was of necessity, because there was a problem with it that made it extremely difficult to boot up once it was turned off, or put in sleep mode (sometimes requiring twenty or more attempts before it would start). Once it booted up, however, it ran fine, and as a consequence I had it running almost continuously for over a year.

Mine has been running almost constantly for 3 years except for a few times a year being shut down to fly from the US to Europe and back.

If you are going to do that, make sure you remove the battery. Almost all laptops will power on just fine with only the AC power source and no battery in place. The reason for this is that if you leave the battery in in constant AC charge, the battery will go bad. I killed a perfectly good battery this way. After being used as a desktop for a few months, constantly being in AC power, the battery would not hold a charge.

Likewise, I rarely shut mine down, though it sleeps at night.

Running a laptop with the lid down can cause heat problems and might shorten its lifespan. Batteries in particular don’t like heat.

I never turn off my computer when flying. In fact, I pretty much never turn it off period except when I need to clean it.

Batteries don’t like heat, so depending on the design and environmental temperature the battery may have a shorter life. Other than that it’s mainly the mechanical parts that wear down: the fan(s) and, if you still have a mechanical drive, the HDD. However, in many cases these will run for years without trouble.

I think it was a coincidence. Using a laptop more or less as a desktop is extremely common and I don’t know anyone who removes the battery. None of them had had premature battery problems in my experience. My personal experience is limited to a few dozen laptops over 15 years, but there must be millions of people using their laptop exactly like this right now without killing their battery.

It’s too late, I’m afraid. I’ve already left the battery in on AC power for years. It’s probably toast now.

And in many laptops these days, you can’t remove the battery, anyway.

Eventually the fans, hard drive, CMOS battery, and other moving/expendable components would wear out, but that’s usually in years or tens of years of use.

While I can believe that leaving it plugged in was bad for the battery once upon a time, I’d be amazed if modern laptops aren’t smart enough about charging to prevent this.

I support the computers (and electronics) of a Co. w/ 45 laptops.
The ones that stay on desks have way more problems with batteries than the ones that travel and therefore use the battery a lot more.
The newer batteries are getting better, but I still see a substantial difference in battery life.

It’s not that the battery goes bad from overcharging, it’s the charge cycles every time its charge depletes, plus the warm interior of a running laptop and the elevated temperature caused by the combination of the two. I think I read somewhere that the best storage condition for a Li-ion battery is to charge it to about half capacity and keep the thing in the freezer!

My old laptop is something like 7 years old now, but I don’t use it often and I always unplug the power cord when not in use. The original battery still holds a charge just fine and can power it for hours. Other folks I know with much newer laptops have already had to replace their batteries, because they use them a lot and the batteries have regularly been charging and sitting inside hot laptops.

OTOH, I have to say that my tablet’s tiny battery still works fine after a couple of years, and I use it daily, and because the battery seems to run down fairly quickly even when it’s sleeping, I keep it plugged in to the charger when I’m not using it.

I think that this advice is obsolete if it was every good advice. I leave my work laptop in the docking station charging 24/7. I have had the computer for 4 years and the battery is fine.

I gave my old laptop to my wife, who then used it as a desktop (powered on all the time, not even sleep mode) for the next 6 or 7 years. It didn’t die, and the battery didn’t die either. (At least, it’s no worse than any 8-year old laptop battery.)

I wonder how much operational runtime you’d get on that battery compared to a new one. I would guess much less. If you never take your laptop off the docking station, would you even know?