5 reasons to hog power outlets when using a notebook

5 reasons to hog power outlets when using a notebook

Summary: Hogging a power outlet can help your battery last longer, give you better performance, and keep other devices charged up, while at the same time keeping you ready for the unexpected.

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TOPICS: Hardware
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Last week, ZDNet's mobile guru James Kendrick highlighted how changing technology means that we don't need to keep our notebooks permanently on charge when out and about. And on the whole he's right, people are needlessly tethering their notebooks to power outlets, meaning that they aren't getting the most out of their hardware, while simultaneously being a pain in the rear to others. 

But there are times when it makes good sense to hog a power outlet, and here I'm going to run through five reasons why you'll find me tethered to the mains outlet.

(Source: iFixit)

#1: Reducing battery recharge cycles

The battery packs inside notebooks have a limited number of recharge cycles before they begin to lose efficiency. This number varies from manufacturer to manufacturer.

For example, the 15-inch Retina-display MacBook Pro I'm currently using — Apple lists that as having 1,000 recharge cycles before the battery is considered "consumed" and should be replaced. I've owned the notebook for 86 days as of today and it has gone through 40 recharge cycles. That's roughly one every two days, giving my battery a theoretical lifespan of about 2,000, or a little under 5 and a half years.

But let's look at this another way. My MacBook Pro has a battery life of between 5 and 7 hours, which means that I could, in theory at any rate, go through two recharge cycles a day, which would shorten my battery's lifespan to about 500 days, which is a little more than 16 months.

The more you use your notebook while it is connected to a power outlet, the longer the battery will last.

With this in mind, I don't like wasting recharge cycles unnecessarily.

#2 – Performance vs. battery life

The performance you get from most notebooks while they are running off battery is more than adequate for most tasks, but when you want to do something more demanding — my example would be running Photoshop — then you have to choose between performance and battery life.

You can't have both.

If I choose battery life then I'm sacrificing performance, and tasks take longer, whereas if I choose performance, I'm cutting into my battery life significantly, and also churning through more battery recharge cycles.

#3 – Recharge when you can

I'm a big believer in eating when you can, sleeping when you can, and using the rest room when you can. The idea being that you never know when the next opportunity might arise.

In recent years, I've extended this to recharging my portable devices when I can. Why drain my battery when there's an outlet a couple of feet away? What's more, why drain a battery when there's a recharge outlet only a couple of feet away and I don't know how long it will be until I'm sitting near another one?

#4 – Expect the unexpected

This is a follow-up on the previous point, but it's worth bearing in mind.

Notebooks tell you how long their battery has left, but bear in mind that this is an estimate. A prediction.  An educated guess. Your notebook doesn't contain a time-travelling circuit and cannot accurately tell you what's ahead.

Recharge now so you don't have to worry — or at least so you can worry less — about it later.

#5 – A charged notebook can be used to charge other things

The battery in my notebook isn't just used to power the notebook, I also use it to charge other devices using the USB port. The more power I have in the tank, the longer I can keep my other devices going. 

Topic: Hardware

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20 comments
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  • Absolutely!

    All good points. My old 2008 era Gateway laptop will run for maybe 1 to 1.5 hours on battery anymore, and I also like to keep my iPhone 4s as charged as possible.
    Everything is battery hungry these days. Whatever happened to going weeks on a double A or two?
    JustWow2000
    • Yup. Like the original GameBoy

      Back-lit LCD screen, AND it ran on AA batteries.
      Richard Estes
  • Spot on.

    I've been using my HP Pavilion Multimedia for 5 years now, and it still retains most of the battery power. I still get 7+ hours of battery because it is connected basically all the time to a power outlet.
    RiverC
  • Left plugged in - Urban myth or dead battery?

    We've had a few batteries which have died from what we believe to be a direct result of laptops being permanently plugged into the mains. Any thoughts? Did we just have a bad batch of batteries, or will an occasional battery drain be a good thing?
    keebaud@...
    • batteries need to be exercised

      Also, an always plugged in battery gets warm and is charges while being warm. Very bad idea with lithium ion batteries.

      I have had the same experience with always on batteries. Most laptop manufacturers recommend you remove the battery if you will be running from the power outlet.
      danbi
    • Left plugged in - Urban myth or dead battery?

      I'm convinced that my first laptop tied such a death (a failed fan actually killed it but at the time, the battery would only last about 10 minutes).
      BRedmond@...
  • One huge error on: "#1: Reducing battery recharge cycles"

    LiIon have two points of death. Recharge cycle and number of months after first manufacture. The rest of you list I agree with but #1, is pretty weak.
    Bruizer
  • James is just being a snob . . .

    James is just being a snob - being condescending towards people who don't do things his way, which apparently is the only true and right way to do things. Seems to be a common theme with him.

    The actual chemistry reasons for keeping a Lithium Ion battery charged aren't as simple as counting cycles - but the overall conclusion that it's better to keep them charged is sound.

    You'll decrease the battery life if you do a deep discharge on them as if they were the old NiCads. Li-ion chemistry isn't the same as NiCad chemistry.
    CobraA1
    • Sorry, but I have to ask ...

      ... James who?
      Ludovit
      • James Kendrick

        "Last week, ZDNet's mobile guru James Kendrick highlighted how changing technology means that we don't need to keep our notebooks permanently on charge when out and about."

        You could just read the article before asking . . .
        CobraA1
  • Plugging a Li-ion in for 30 minutes does not make a charge.

    A charging cycle for these is not what you imply. From Apple's tech note:
    "A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge."

    See: http://www.apple.com/batteries/
    raleighthings
  • Fantastic post

    Great post Adrian. Really enjoyed the part discussing how important it is to charge when you can. Our computers can be at many risks, and it takes more than proper internet security to keep them out of harms way, and one of them is product usage. Good read.
    CharlesTrentham
  • Careful with keeping your battery at 100% most of the time

    Keeping the battery charged most of the time at 100% is not healthy for the battery either. Nor is dropping the charge of the battery under 20%. Keeping the battery soaked with electrons for long times affects its ability to store electrons, if you accept the term, it petrifies it. However if you drop the charge too low, since the battery still needs some electrons to keep the chemical bonds inside working you are putting a big strain on it. So if you empty it aggressively and then leave it empty for a good while, you are again damaging it.

    If you work plugged-in at all the times, its better to keep the charge at around 50-60%. There is battery software that let's you set that maximum charge. For example Lenovo laptops come with widgets or system software that let you do that. Also, don't let it drop below 20-25%.
    The obvious disadvantage is that you never know when you need to be fully mobile and therefore when you could really use that 100% charge. However, on a typical day you might be able to predict it, while just before a longer trip or a holiday you could just charge it to maximum.

    Temperature also affects the life of the battery. A battery charged at 100% sitting for days at 50degress (C) will die faster than a 60% battery sitting at 40degrees (C) which will die faster than a 60% battery sitting at 5degrees. If you have a detachable battery, charge it to 50-60%, put it in a self-sealing bag and put it in the veggie compartment in the fridge (dont freeze it in the freezer). The cold will slow down the chemical decay and the charge will be optimum. This works especially well if you bought a backup battery for your laptop but you are don't need it for a while.

    A charge on a Li-Ion battery is when total discharge amounts to 100%, regardless of what you re-charge meanwhile. So if you start with your battery at 100%, then use it to 60% and then recharge it completely, all you really used is 40%. Next time time when you use it from 100% to 40%, you just finished a full cycle, even though the battery has 40% left and has been already charged once. So no matter how often do you recharge it, a full charge is when everything that you used amounts to 100%.

    Time, temperature and usage patterns all affect your battery. With care, your battery might last 4-5 years. Without care, 2 years tops.
    deprimat
    • Batteries and heat

      Deprimat, good point. I think buying a good laptop cooler is a good investment given than adding one to my laptop lowered the internal temp by 30 degrees F. Keeping the battery cool is just as important as keeping the CPU cool.
      rphunter1242
  • those temperatures are very high

    Where are you putting your computer, that it is exposed to 50 dec C? That is 122 deg F! Are you in the desert? Even 40 Deg C is high that is still higher than 100 Deg F. Std Room Temperature is taught as 25 Deg C. Which is 77 deg F, which in turn is probably higher than you keep your home or office.
    I don't see the logic in counting only 100% charges as bing the recharge cycles, common perception is that any time you charge your batteryit is a charge cycle. It does make sense that if you are to keep it plugged in continuously it should have its battery removed. (if you can)
    dhays
    • This is Phoenix.

      Our field guys have laptops in their trucks plugged in most of the time. Inside a car is easily 140 F in the summer when it's 115 outside. They don't hold a charge for long in that heat. We don't even bother to replace dead batteries. Lead-acid vehicle batteries don't last much more than 2 - 3 years here either. The heat kills them faster than the cold.
      NotMSUser
    • old dirty laptops

      ~50 degrees C is what you will get inside most 2y+ old laptops that were never cleaned, serviced and in which the thermal paste between the chips and the coolers was never changed. which is probably the vast majority of laptops out there.

      these machines sit between 45-50 C on idle, when the room temperature is around 24 C.
      when you start hammering the CPU and the GPU, most machines spike to 65 degrees C.
      if you see your laptop getting to 65, you are sitting on a time bomb.
      the coolers will spin at 100% most of the time, wearing them out faster, the CPU will drop voltage and Mhz to keep the temperatures manageable and it's all fast downhill from there. after a few more months, the laptop will get even hotter and at the next full shutdown, if the hot chips will cool down too abruptly, they will unglue from the mobo. usually this happens for the GPU chip (CPUs rarely fry as they manage their voltages better).
      since its not easy to change the GPU, you will have to change the entire mobo for a 3rd of the price of a new laptop. most people just buy a new one. that's what happens for 80% of the people out there.

      people use laptops in beds, on dirty tables and on places without proper ventilation underneath.
      they eat, smoke and shed hair on them. you wouldn't believe what gross stuff accumulates inside a neglected laptop used for a couple of years.

      my friends work in a laptop repair center, the most important tips they could give me was to keep the temperatures as low as possible, use a cooling stand for those hot summer days AND to bring the laptop for thorough cleaning every 6 months.
      deprimat
  • Battery charging 'cycles'

    Note that with lithium ion batteries, which are in most laptops measure 'cycles' as full charge, to full discharge (point at which the laptop will automatically shut down), which is about 20% short of a full discharge, which is a BAD thing to do to a lithium ion battery. If you use it down to 80% power level, then recharge, that is only 1/4 of a recharge cycle. Something to think about.
    rphunter1242
  • Take Lithium for depression

    See BatteryUniversity.com for some really good information about charging Li and LiPo batteries.  It's best to charge to one's selected full level  -- and better not to let the battery charge to the most it can hold.
    ka5s@...
  • URL for the above

    This board will noy accept the URL as a hyperlink.

    " http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries "
    ka5s@...