Why Your Notebook Battery Life Never Quite Seems Equal to the Claims

By  |  Wednesday, April 1, 2009 at 9:06 am

[A NOTE FROM HARRY: Please welcome Patrick Moorhead of AMD to Technologizer’s roster of contributors. He’ll be writing both topics relating to his day job and others that simply stem from his experiences as a gadget enthusiast.]

Do you ever feel like the actual battery life on your notebook never quite equals the information that appears in promotional material? For example, you may see “up to five hours,” but actually get about half that.  Well, you aren’t alone.  I hear it all the time, and if you do a quick Twitter search on the topic, you’ll see lots of discussion.

I can assure you that no devious plot exists to mislead you. It really comes down to a few simple factors.

#1: Measurements are best case: Like a car’s “highway miles per gallon” which gauges the best case (cruising at a sustained speed for an extended period without stop-and-go driving), notebook battery life is typically based on MobileMark 2007. This benchmark primarily measures battery life while the notebook is doing nothing–not even wirelessly connecting to the Internet. A “city-driving” equivalent of notebook battery life doesn’t exist…yet.

#2: Different strokes for different folks: We all use notebooks differently, and therefore will see different battery durations.  Some watch HD web videos on YouTube, some may just do email, and some play more games than others. all of which will mean varying battery life.  You can see this data from AMD here that shows the phenomenon.  (Disclosure: I work for AMD) This also shows that battery life varies depending on the combination of components inside a machine.

#3: Battery life varies over time: The longer you own your notebook, use it, charge, and recharge, over and over again, the more the battery loses its effectiveness.  So theoretically, your longest battery life will be on the first day you crack open the packaging.  See all the people selling new batteries for old notebooks?  Some even say that battery life is variable with heat.

So what should you do?

  • Grade battery life on a curve–let’s say, 60% of the claimed performance. If the label says 10 hours, my guess is it’s probably only about 6 hours in real use.
  • Ask your retailer and systems providers to provide the “city miles per gallon,” or, using the tried and tested cellphone analogy, “talk-time.” They all have Web sites–and when all else fails, you can ask them over Twitter.

I may have not added back 40% of your battery life, but hopefully you know why you only get 60% of it!

Pat Moorhead is Vice President of Advanced Marketing at AMD. You can find him on his AMD blog, Twitter, FriendFeed, and LinkedIn. His postings are his own opinions and may not represent AMD’s positions, strategies or opinions.


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5 Comments For This Post

  1. CherokeeCasinoTulsa Says:

    i know depend of the use of the notebook.

  2. Sal Weed Says:

    Pat, nice summary here. One thing I don’t understand is why the mobilemark guys don’t just change their benchmark to reflect what end users may actually do when they are pounding on the system. You are part of this org, can’t you make the changes? I game, do HD vids on my laptop. I want to know the battery life doing that.

  3. Hal Speed Says:

    Sal, I’m one of the people at AMD that participates in BAPCo and I wish it was as simple as you describe to improve MobileMark. First, BAPCo was chartered to focus on business users instead of consumers that game, play movies, etc. So we need to expand the charter of the organization to include consumer applications. And second, at the end of the day AMD has one vote. We are an advocate for the end user but that doesn’t always align with the agenda of some of the large companies that also have a vote. That doesn’t stop us but it can slow things down.

  4. Snarky Truth Says:

    I think it will take a major class action lawsuit before retailers and computer OEMs will change. They know its deceiving and are too lazy or apathetic to make a change.

  5. AudiGuyy Says:

    Your post made me think, I always attributed the lower batterylife to something I was doing as a consumer, but now that I have read through the twitter conversations, I came to realize that the measurement is misleading and needs to change and it wasn’t just me. I also have been doing research on Contrast Ratio and Dynamic Contrast Ratios in HD TV’s to educate myself before purchasing.
    Same issues apply – but granted worst than the PC battery issues.
    Manufacturers need to be held to an honest and open metric system, consumers need to demand this and hold off purchasing until the retailers make it happen.

    I applaud AMD for leading this charge, now lets all hope Intel is customer centric enough to help fix it!
    Bet if BestBuy demanded it, they would fold!

    I also hope guys like you and Harry apply MORE pressure!!!