Batterygate Part 2 - Lies, Damned Lies, and Statistics

Editor's note: This is the second part of our Batterygate Analysis, we recommend that you also read the first and the third part:
Part I: The nits picking begins
Part III: Box Shaped Box

To quote the great Steve Jobs, paraphrasing Pablo Picasso - "Good artists copy; great artists steal." And in the words of British Prime Minister Benjamin Disraeli, popularized by the great Mark Twain, "There are three kinds of lies: lies, damned lies, and statistics."

One of the things that seem a bit obscure is what exactly constitutes a "damned" lie. We see many lies all around us, like "Consumers find model numbers easier to compare than MHz and cache sizes." But what makes a damned lie? Twain and Disraeli may have thought the answer was obvious at the time, possibly a lie that makes use of truth, twisting it to its purpose. Such an act is more heinous than a "simple" lie, which is just a falsehood. In the modern age of cross-licensing settlements, business method patents, and copyright infringement lawsuits against soccer moms, we see damned lies all the time; they're even easy to spot. Take for example the weekly sales flyer from a major store chain that sells laptops, like Office Depot or Best Buy and you can see that next to the line that mentions the battery life on a laptop, there’s a little footnote indicator. The footnote turns out to point to a tiny line of text buried on the page that mentions that battery life "varies" or that it was tested under specific circumstances; which renders those claims rather irrelevant since they’re technically true, but only in specific circumstances. This is using a little bit of truth (a specific case) to lie to consumers (print ostensibly unrealistic performance claims) for financial gain.

These are damned lies.

Of course calling them such can get you a nasty email or phone call from a company PR rep who will try to explain that these numbers are true, and saying otherwise is tantamount to slander or libel. But most of us who are familiar with the tech industry know what’s up - basically any numerical performance claim with a footnote is a damned lie, designed to fool people who don’t know better into thinking it’s true. If it was really truth, there would be no fear of getting sued over such claims, so there would really be no need for footnotes and fine print to cover one’s legal ass.

Thus damned lies are quite easy to spot, just look for anything that involves a number and a footnote. The key part is really in the numbers, since numbers tend to be very specific. As for batteries, well… a battery is really a box full of chemicals that stores energy and the releases it as electricity. To model a battery, you need to use statistical chemistry, so you can imagine what kind of territory we’re in now! So it should come as little surprise to many that just as there are games being played in the world of software, so too are there games being played with hardware.

Pop Quiz!

Obviously not everyone knows the details of how a battery works, nor should they have to. We don’t expect everyone with a driver’s license to know how to build a car. People can usually get by with learning a few simple rules. But in the case of batteries, not all of these are well known.

It’s now summer and many people are glad to be out of school. Except for those heading back for summer school, you have not been forgotten. In the spirit of the season, and since some people may need a bit of remedial classes in the care and feeding of laptop batteries, here’s a little quiz we whipped up after some time spent at Battery University.

Think you’ll pass? The answers are on the next page. Please do not write directly on your screen, and only use a number 2 mouse, as others may smudge your mouse pad and not be read by the online scantron.

Useful info:
Ah/mAh = Amper hours/milliamp hours, a measure of battery capacity
Wh/kWh = Watt hours/kilowatt hours, voltage x Amper hours = watt hours

For the purposes of this test, ignore variables in battery chemistry, assume lithium ion rechargeable (typical laptop battery) as default.

1. True or false: A specific battery’s capacity in mAh is affected by the environment.
   A) True        B) False
2. When comparing two batteries the best value to look for is…
   A) Volts        B) Amp Hours        C) Watt Hours        D) Cells        E) Weight
3. A fully charged lithium ion battery from a laptop at room temperature (25C/77F) permanently loses how much capacity per year?
   A) 1%        B) 5%        C) 10%        D) 20%        E) 50%
4. The battery from #3 is left in a plugged in laptop that keeps it near a temperature of 40C/104F all the time, how much capacity per year does it lose?
   A) 5%        B) 10%        C) 25%        D) 35%        E) 50%
5. A fully charged battery at a higher temperature will produce _____ energy compared to one with the same charge that is cooler.
   A) more    B) less        C) the same     D) negative
6. If a battery has its capacity in mAh on the label, the standard rate of discharge used in determining that rating was
   A) 1 minute    B) 1 hour    C) 2 hours    D) 10 hours    E) 20 hours
7. A battery that is discharged intermittently at high and low rates will appear to have ____ capacity compared to one discharged continuously at the average rate.
   A) more    B) less        C) the same    D) random
8. A lithium ion laptop battery would suffer the least permanent capacity loss if stored
   A) in the laptop        B) on a desk    C) in a refrigerator    D) in an oven    E) in the dark
9. The battery from #8 would be best stored with what amount of charge?
   A) completely full    B)  almost full    C) about half    D) almost empty    E) completely empty
10. If a battery lasts for 20 hours at a discharge rate of 1/20th its rating (0.05C), about how long will it last at the rated discharge rate (1C)?
        A) 1 minute    B) 30 minutes    C) 1 hour    D) 2 hours    E) 10 hours