Zen and the Art of Battery Life

November 23, 2009 Hardware, Site News — Kyle Wiens

The lithium-ion polymer batteries shipping today are amazing creatures, packing greater energy density than both the nickel-based cells of yore and the first generation Lithium-ion cells. Yet most people are unaware of how to properly manage the life of this new technology. What you do on your laptop is your own business, but following these tips will let you do it longer (that’s what she said!). Most of this info holds true for iPod batteries as well, so you might as well learn the ropes now and reap a lifetime of rewards — at least until scientists come up with new, better, battery technology.

Step 1: Learn The Tech
LiIon cells charge in two stages. Stage one is a fast charge at constant amperage and steadily increasing voltage. When the battery reaches a 70- to 80-percent charge, the second stage begins, gradually decreasing the current applied to the battery while maintaining constant voltage until the battery is fully charged. This second stage is called the trickle, or topping-off charge, and it takes two to three times as long as stage one.

Apples charge stages graph

Apple's visual description of charge stages

Contrary to popular belief, it doesn’t matter whether you completely drain and completely charge the battery every cycle, or grab a few minutes of charge time whenever you can (with regard to battery life, at least).  But the latter practice will eventually make your reported battery-charge and remaining-life times inaccurate. To make sure the battery knows how much capacity it has, every once in a while you should completely discharge then fully recharge it. This keeps the electrons flowing through all the cells and calibrates an internal mAh counter.

Charges are cumulative, and you do not have to completely discharge the battery every cycle.

Step 2: Use It or Lose It — or Replace It
If you store your LiIon battery with a full charge, it’ll irreversibly lose about 20 percent of its charge capacity per year. If you aren’t going to use your machine for a while, leave your battery partially charged (40 to 50 percent). Even then, LiIon cells will lose capacity over time, but will do so more slowly at cool (not freezing) temperatures. Think about that when you’re choosing whether to store your old iBook in the basement or the attic.

Apple will sell you a new battery for any of its current laptops for $129, but the company no longer sells batteries for most of its older models. Fortunately for you, iFixit sells batteries for every portable Apple has made in recent memory. If you don’t get a battery from us, know that the main concern with after-market batteries is age: It’s best to buy a recently-manufactured battery and not just a “new” OEM battery that was made five years ago and has never been used.

Step 3: Gauge It
Battery capacity is expressed in milliamp-hours (mAh) or watt-hours (Wh).  The Late 2009 plastic unibody MacBook has a 60 Wh battery, so its claimed 7-hour battery life tells us that the MacBook sips just 8.6 watts. (This battery runs at 10.95 volts. Quick refresher from high-school physics: P = IV, so 60 Wh = I * 10.95 volts. Solving for current (I), we learn that this battery stores 5.48 amp hours, or about 5,500 mAh of juice.)

Your battery consumption can vary depending on how much the computer components are used (hard drive access, burning DVDs, using Wi-Fi), but the battery has a finite amount of capacity that only decreases over time.

On a Mac, you can easily determine your battery’s remaining capacity with third-party utilities such as Battery Health Monitor (shown above) or Coconut Battery, but you can also use Terminal (located within /Applications/Utilities). Type “ioreg -l -w 0 | grep Capacity”. The first item, CurrentCapacity, is your battery’s current capacity in milliamp-hours, whereas DesignCapacity lists the battery’s original capacity. System Profiler (on every Mac in /Applications/Utilities) also shows some information in the ‘Power’ profile.

Step 4: Recycle It

The Lithium inside these batteries isn’t super toxic (unlike most other batteries), but the world’s supply of lithium is finite. It’s gotten a lot more convenient in recent years to recycle batteries. Home Depot and Radio Shack will take back and recycle batteries at most of their stores. To recycle devices with integrated batteries, the fabulous e-stewards program publishes a list of certified e-recyclers that are properly accounting for their waste stream rather than shipping it overseas.

Random bit of trivia: Unused lithium batteries have been rumored to be a common source of lithium for making methamphetamines, but the ionized non-metal form of lithium used in Lithium-Ion batteries doesn’t work for this purpose.

Introducing iMac and Mac mini repair manuals

November 19, 2009 Hardware, Repair Guides, Site News — Kyle Wiens

We are proud to announce the release of over two hundred repair guides, covering every Mac mini and most iMacs produced by Apple since 2004. All iMac and Mac mini repair manuals are immediately available for free on iFixit.com.

The repair manuals include in-depth disassembly guides, model identification tips, troubleshooting techniques, and upgrade information. The 241 new repair guides use 1,452 photos to clearly communicate each step of the repair.

iFixit repair guides are well known for world-class photography and clear, concise step-by-step directions. We are also launching an iMac parts store with hard drives, RAM, power supplies, disassembly tools, and more.

Pressed for comment, our CEO Kyle admitted that: “We have been pummeled with requests for iMac parts for years, and I finally couldn’t take it anymore. That’s right, we are now accepting money in exchange for iMac parts.”


  • The iMac repair manuals cover all 17″ and 20″ machines manufactured since 2004, including both G5 and Intel models!
  • 184 iMac repair guides use over 1,000 photos to illustrate the process of diagnosing and repairing each machine. They cover all aspects of the iMac, including removing the glass panel, upgrading the RAM and hard drive, and replacing the logic board.
  • The iMac parts store includes RAM, hard drive, and optical drive upgrades, as well as replacement parts such as power supplies and glass panels.

Mac mini

  • The Mac mini repair manuals cover all iterations since its inception in 2005. The list includes G4, Intel Core Solo, Core Duo, and Core 2 Duo machines.
  • Our experts have completed a total of 57 Mac mini repair guides. They cover accessing every part inside the Mac mini, including replacing the RAM, swapping out the wireless card, and removing the logic board.
  • Mac mini parts include RAM, hard drives, and optical drives, as well as enclosures allowing the installation of two internal hard drives.

We’re super excited to announce this. Our technicians have been working hard all year to make this happen, and I’d like to thank the entire team for their wonderful work. I hope it’s useful.

Droid Teardown Contest Winner

November 11, 2009 Hardware, Teardowns — Miro

Our war with the Droid is over, and we’ve won! A bounty hunter / iFixit user by the name of Dr. Wreck stepped up to to plate, ripped apart a Droid, and posted his teardown on our site.

The phone was quite a handful to take apart, having a multitude of hidden screws and latches. Interestingly enough, the sliding mechanism consisted of two rails that were imbedded within the screen portion of the device, providing a simple and effective method to slide out the keyboard. Sadly, no aliens or hidden messages to Princess Leia were found inside.

We’ve awarded Dr. Wreck $300 cold hard cash for his valiant effort. One Droid had to be sacrificed for the cause, and we’re glad it wasn’t ours (for once at least).

Feedback Loops

November 5, 2009 Answers — Kyle Wiens

I recently learned a lesson on the importance of feedback loops. We have lots of people participating in the Answers beta, and I reposted a couple questions there from our public discussion forums. I was hoping that it would produce some helpful solutions. My approach turned out to be a mistake, but not for the reason that you’d expect.

People actually posted several thought-out, interesting answers. The community voted some higher than others, and some of the answers . What did I do wrong? I got several answers to the user’s problem, a number of which looked viable to me. But I didn’t know which answer to accept! It turns out that the information that I think is useful is probably different than what the person who asked the question actually needs. I wasn’t able to honestly accept an answer because the question wasn’t mine!

Accept this

This really illustrates the need for our ‘accepted answer’ loopback mechanism. One of the really fun things about repair is that when you do find a solution, you know for a fact that it worked. There is no wishy-washy epistemological debate. Either what you suggested works to fix my problem, or it doesn’t. Accepting an answer communicates this success to the world, and to the person who posted the solution. This feedback is hugely encouraging to people posting answers.

Accepting answers solves an important issue with online communities. Troubleshooting forums are traditionally full of ‘hit and run’ questioners: people who post a single question and then disappear forever, never communicating the end result to the community members who tried to help. There are two problems with one-off questions: over time, it discourages established members from helping newbies, and it doesn’t indicate to people who stumble upon the forum whether what they are seeing is actually a useful answer. Establishing a social norm of saying ‘thank you, that solved my problem’ solves both these issues.

Two perspectives

The asker is not the only one who benefits from answers. There is another intended audience for the answers people post: the community at large. There are actually two right answers to every question: the response that fixed the asker’s problem, and the answer that the community as a whole finds most useful.

There is an immediacy to the first answer— we strive to provide timely, helpful solutions to problems people post. But what’s wonderful about our system is that it gets better with age! The more people vote up answers, the more views it will get and the more people will be able to edit posts to make them better.

When you help people here, you aren’t just writing answers to questions. You are building a long-term knowledge base of solutions to problems people encounter about devices. Because everything is editable, the answers to more popular questions will actually get better over time. The world needs this information.

Wanted: Motorola Droid Internals

November 4, 2009 Hardware — Miro
Wanted: Motorola Droid Teardown

Wanted: Motorola Droid Teardown

We love making teardowns, but we’re preoccupied at the moment with trying to change the world and just don’t have any spare time!  We’re turning our preoccupation to your benefit: we want the public’s help in acquiring a teardown for the Motorola Droid.  We’re giving cold, hard cash to the first person who posts a teardown of the Motorola Droid onto our website. That speedy contestant will get $300!

Contest Rules:

  • Purchase your very own Motorola Droid by any means necessary. We suggest lining up in front of Verizon’s store on the East coast, as they have a three hour advantage over us Western folk (but it was a pleasant 80 degrees today, so take that East!).
  • Create a Droid teardown on our site by snapping excellent photos and writing witty text.
  • Be the first user to post the Droid’s internals. The person with the first “layout” shot wins $300 USD. Example layout shots: iMac 27″, PSP Go, Nikon S1000pj.
  • The contest ends on November 13th at 11:59 PST, a week after Droid’s release.

We’ll update this post to announce the winner once the contest is over. Anybody is welcome to participate, but only one person will win!

Congrats to Dr. Wreck, the first user to post a Droid teardown for our contest! Read the full scoop on Dr. Wreck’s teardown here.

Introducing Answers: A Collaborative Repair Community

November 3, 2009 Answers, Site News — Kyle Wiens

I am proud to announce iFixit Answers, a collaborative repair community of people helping people make devices work longer. We are launching the private beta today, but we will be inviting more people throughout the testing period. To get an invite, add your name to our list (we’ll be sending out invites to people on the list as we have room) or, if you want to be bumped to the front of the list, write a teardown!

The world has a problem with rapidly consuming devices and tossing them aside, ignoring long-term environmental impact. With your help, we are going to change that. I’m confident that we can change our culture of ephemeral ownership.

Fixing a Mac, the iFixit way

iFixit has helped hundreds of thousands of people fix Apple hardware. Just last month we shared our repair knowledge with over a million people in 175 different countries. Our internet-scale troubleshooting and repair documentation has made electronics repair accessible to people all over the world. In this new and exciting time, you can leverage your knowledge about hardware to make a difference not just to people next door, but to communities halfway around the world.

Answers is a natural progression from our successful forums. The community will have complete control over the content on Answers, and the system will be collaboratively managed by you, and other people like you. Every question and answer can be voted on by anyone and edited by members of the community.

As we were designing Answers, we had four guiding imperatives:

  1. It’s important that posts get more useful over time. It’s not uncommon for a traditional repair forum response to become the canonical source for an answer to a problem, only to get outdated and stagnant as technology changes.
  2. It’s important that we recognize expertise. It matters if the author of an answer is a professional technician, or has helped 200 people fix their problems.
  3. It’s important to make helping people fun. There’s a rush that comes from helping someone solve a tricky problem, being recognized by people for the research you put into a question before asking it, or testing your hardware diagnosis mettle against others.
  4. And most important, we need to close the feedback loop between the people answering questions and those asking them. Repairing things is uniquely tangible — when you use a solution proposed by someone, you know for a fact whether or not it worked. Finding out that the answer you gave someone actually fixed their problem is one of the greatest feelings in the world.