Leaving Your Laptop Plugged in Harms its Battery?

by: - Last updated on: August 7th, 2016

There has always been a tight controversy between keeping a laptop packed with the battery plugged-in at all times, or not. Many have wondered if this overcharging process, if we are allowed to call it so, may reduce the battery life over the years or, even damage the product in some way. As a laptop owner myself, I had troubles choosing a side but, after a long search on the web, I have gathered all the results I have found under the same roof and today, I’m about to make them public.

Taking a deep plunge into the mystery which has wrapped many laptop users in darkness, by not knowing whether they should keep their device plugged-in with/without a battery or simply use it as a smartphone, and charge it whenever the energy is depleted, we set ourselves to present the most relevant motives of each side, while helping you take a decision, by yourself.

charging laptop

How should a laptop battery be used

Although highly unlikely, you may not be aware of the damages brought over the years to a plain old laptop battery. In some cases, depending on the manufacturer of the battery and even of the one that assembled the laptop, a brand new shiny product which was guaranteed to supply between two and three hours of juice on a regular charge can degrade very fast. We have heard cases when laptops, mostly from Dell, had a battery so bad that after a year, the user could only squeeze around 5 minutes of life – meaning that he would have to use a power outlet at all times.

Besides on the pure use of a battery, there are also other factors which influence the long-life of this product, like the laptop’s own settings. If the manufacturer was so kind to include power saving modes or settings to stop the battery from charging when it’s above 93%, let’s say, then you are in luck. If not, here’s a tale of the most known theories and how you must react:

  • Exercise the battery – as a product meant to be used, the battery should not be kept in dark place for a long time, without being drained once in a time. Those who wish to use the laptop solely on the power transmitted directly from the AC plug, should insert the battery at least once in a month, let it charge and then drain it up to 15%. This will ensure that the battery is getting some action from time to time and the chemical substances within will surely appreciate it.
  • Store the battery when stationary – those who are certain that they are not going to use the battery in the next couple of months, because they rely just on the power plug, without moving the device at all, should best charge the battery until 33%-40% of the maximum juice and then store it inside a refrigerator or a cold place (but not colder than 32F or 0 Celsius). If the battery is taken out of the fridge once in a while it will damage the product more than ever.
  • Don’t let it discharge completely– a fact that I wasn’t aware of until a couple of hours ago was that whenever the laptop battery went under the 15% mark, it suffered quite some complications. It seems that it is mandatory to shut down the equipment or plug it under this limit, this being the main reason why batteries are slowly killed. Moreover, if a battery is discharged below the 5% mark or even completely, permanent faults will occur and the product looses a significant amount of capacity. Discharging completely is only allowed on older batteries (not Li-ion) with memory effects.
  • Using the laptop while charging the battery – the myth that a battery will have to suffer under these circumstances is absolutely busted, at least for notebooks. While charging, a part of the juice will go into actually powering the device while the spare will be instead into replenishing the battery. The only disadvantage is that the cells will be recharged slower.
  • Fast batteries can be somewhat fixed – those with batteries that die out prematurely can be somewhat saved, by leaving to power the laptop until the operating system complains, pulling it and recharging it, but only after the battery has cooled down. The recharging process must be done while the laptop is offline, to avoid any extra thermal stress. Repeat the procedure a couple of times and improvements should be seen.

Laptop battery cycles

Just like we’ve explained in a previous article – Why has iPhone’s battery life remained the same – every battery has a life cycle. Thus, if your iPhone can last for, say, 400+ recharge cycles, then obviously, your tablet’s or laptop’s battery will also have a similar thing. Here’s another explanation:

You shouldn’t technically leave your laptop plugged in all the time, but you certainly don’t need to deep-cycle it a few times a week. Furthermore, the recommendation for monthly battery usage isn’t just for capacity preservation: it’s mostly so the charge indicator can maintain accuracy as the battery’s capacity decreases naturally over its lifespan.

Therefore, when you buy a laptop, don’t just look at how many hours its battery can last, but also check how many cycles it actually has. Remember, a cycle is from 100% fully charged to completely depleted. A moderate use, it seems, will make your battery degrade by 30% during a year and the battery should “live” for about 350 charging cycles. But, this is just a ballpark figure.

Should the battery be kept inside the laptop or not?

Dead battery sign

Indeed, that is the question. After acknowledging all the advices presented above, the short conclusion is that you should definitely keep the laptop battery plugged at most times. This will ensure that the product is exercised and because many laptops have a stop-charge function, which protects the product from overcharging (when the level reaches 90%, the power will be switched from charging the battery to supplying the laptop, and the charging process will stop) the battery will be kept safe. While the battery is inside the laptop, the following things will happen though:

  • High charge – unfortunately, the 90% mark is a bit too high for a battery. As we’ve mentioned earlier, an almost half percentage is ideal for this kind of product. While the battery is stored with this high charge, chemical process will react faster and the aging of the product will happen a bit faster.
  • High temperature – because the battery is situated to a 60 degrees hot laptop, the heat will disperse onto the battery itself, forcing it to degrade faster and making it lose precious life. Vice versa, the high charge of the battery will translate into higher temperatures that will heat the laptop itself.

Although these two disadvantages cannot be overlooked, they usually damage the battery less than in cases where the product is not used. I have been using this tactic in the past four years and it has not failed me yet. Moreover, it protected me when power outages occurred. How about you? Do you keep your laptop battery at all times?

Photo Credits: sparechangemedia

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  1. I never remove my battery from my laptop and my laptop is 6 years old and always use the power cord, at least once every 3 months, I unplug the power cable and use the battery to about 10 minutes left on the battery and then hook up the power cord to charge the battery and use the laptop

    1. I have done the very same thing. 5 years straight with my battery plugged and it has only lost around 20% of its capacity; still sucks though, I can only squeeze one hour and a half, meaning I lose the final 10 minutes of an ordinary movie if I’m traveling.

      1. Hey,
        I have a toshiba satellite c665d m5010.
        I always keep it plugged in.
        Would it deteriorate the battery life?

          1. Thanks Alex.
            I have one more question though.

            Does charging a laptop battery from 93% same as charging it from 80%.?

            I mean when i am left with 93% remaining ,
            should i plug it there and then or use it up a bit and plug it at a point somewhere near 80%.?

            Does shallower discharge cycles affect the battery too much ?

          2. No, shallower cycles do not affect the battery more than regular charges. But I cannot say that do more good. I believe is probably the same thing, as long as you don’t drop under the critical 15% limit.

            Also, it would be chaotic to leave the laptop discharge until 93% or 80%, because that would mean around 20 minutes and you will be forced to constantly plug/unplug the device. As we’ve mentioned above, it is best to leave it charging or, if you want to move it around the house or something like that, unplug it until 30%-40% and then recharge.

    2. I always removed my battery and followed the tips above and it worked great for 2 years. I gave my laptop to some friends who didn’t remove the battery for a long period and now it only lasts for about 30 minutes. I guess it applies to some laptops.

  2. I am using HP Envy 6 1002tx (a month old). I mostly keep it plugged in while i use it. Is it the right thing to do? Also I use it for around 12hrs a day; mostly surfing net, reading e-books, and some engg stuff.I am too addicted to resist.

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  3. That seams to be only true for a Mac. My MBP was plugged in for a year straight it went from 5h of battery life to 15mins then finally to 0. On the other hand, at work there is a Dell Laptop that was plugged in for 5+ years and still gets 3+ hours of battery life. It all depends on the battery.

    1. I also believe that it depends on the battery but only in some cases, where the battery is really weak and loses its recharging cycles fast. It’s curious though, I have been hearing that Dells are quite the bugger when it comes to battery.