1. cmaier's Avatar
    Dude, you're wrong. You can't go from voltage to mAH like that. It doesn't work like that. Lots of batteries are 3.7V and have mAH ranging all over the place, and you are just making up physics now.

    Also, mikec, no friend of mine, did not slander you. People love to throw that term around, but there's no slandering going on here.
    07-11-2007 12:03 AM
  2. cmaier's Avatar
    Here's a 3.7V battery with 2500mAH (li-poly) (http://www.batteryspace.com/index.as...OD&ProdID=2613)
    Here's a 3.7V battery with 3000mAH (http://www.radioshack.com/sm-lenmar-...i-2439467.html)
    Here's a 3.7V battery with 4000mAH (http://cgi.ebay.com/3-7V-4000-mah-U-...QQcmdZViewItem)
    Here's a 3.7V battery with 5000mAH (http://www.alibaba.com/catalog/10687...V_5000mAh.html)

    If you want to learn how volts and mAH are really related, feel free to PM me.

    And I still say, judging by the relative size, apparent current draw, and relative lifespan of the battery that it is most likely >4000mAH. The way apple got better life is, in large part, by using a more capacious battery.
    07-11-2007 12:11 AM
  3. oalvarez's Avatar
    True, some are not up to the specs, but those seem to be defective or early samples of the supply. Apple has exchanged them all .
    i like to think i'm a realist, or employ sound logic but this one i'm having a little bit of
    difficulty with.

    "Apple has exchanged them all?" ok, fine. i suppose that could mean (imply) that each and every defective phone (no matter of the defect) was successfully exchanged as opposed to accepting them back with an early restocking fee, or without.

    is that the point you're trying to make or are you saying that each and every iPhone battery related instance has been dealt with, and exchanged with a new one?

    can one infer such?
    07-11-2007 12:12 AM
  4. archie's Avatar
    i like to think i'm a realist, or employ sound logic but this one i'm having a little bit of
    difficulty with.

    "Apple has exchanged them all?" ok, fine. i suppose that could mean (imply) that each and every defective phone (no matter of the defect) was successfully exchanged as opposed to accepting them back with an early restocking fee, or without.

    is that the point you're trying to make or are you saying that each and every iPhone battery related instance has been dealt with, and exchanged with a new one?

    can one infer such?
    Yes. That is to say Apple exchanges the iPhone/battery if the customer brings one of these subpar batteries in that does not live up to it's published specs. There may of course still be some unreturned iPhones with these initial samplings (or whatever the reason is) but the number is not nearly as high as the first few days.

    As quoted: "Apple has exchanged them all and these reported occurances of batteries not performing as published are fading away."

    I suppose a conspiracy theorist could assume this was allowed so that they could push more phones through the channels to have virtually/fake higher sales figures.

    I don't know why I added that last part. I guess just to beat surur to it.
    07-11-2007 12:46 AM
  5. cmaier's Avatar
    Archie - I'm still waiting for a physics lesson where you explain how 3.7V=300-400mAH.
    07-11-2007 12:49 AM
  6. mikec#IM's Avatar
    Now why would you first choose to quote this:

    "no other manufacturer that can touch this kind of battery efficiency and battery life that Apple provides in the iPhone"

    and then choose to quote the entire sentance?


    You know what I am talking about, but I'll say it again: Apple can make batteries last longer than any other phone manufacturer out there.

    mikec, you and I both know that Apple doesn't make batteries and to insinuate that I think otherwise is asinine and a character defacing.

    I have not officially asked that you stop your slandering actions but I am doing so now.
    Archie,

    To quote cmaier, "it's not slander if it's true." And not, I am not slandering you, just repsonding to your posts.

    First, you need to read what you wrote - you said Apple made battteries. (now if that what a mistake, just say so and move on).

    Second, 300-400mah? You have ZERO idea what you are talking about. There is absolutely NO WAY that it's a 300-400mah battery. I will bet a free iPhone to everyone on this thread on that, and better yet, if I am wrong, I will never respond to one of your posts again.

    Are you confusing charge cycles with mah?

    It's common knowledge that in cell phones/smartphones, more mah means longer battery life (yes, voltage plays a factor, but mah is where the rubber meets the road.
    07-11-2007 09:17 AM
  7. cmaier's Avatar
    Hey, Archie, here's a little physics lesson for you. I'll ignore parasitic effects to keep it simple.

    Voltage is a measure of potential (the easiest way to think about it is that a higher voltage between two points means a higher difference in charge between those points). Amps is a measure of current.

    On a battery, ideally, the potential is constant. In this case, 3.7 volts. No matter what the phone is doing, that battery does its best to keep the potential across it's two terminals at 3.7 volts.

    Now, the phone will require a different amount of current depending on what it is doing. If the screen is on, that requires a certain amount of current. Each time the CPU clock transitions, it requires a certain amount of current. Each time a logic gate on the CPU changes state, it requires a certain amount of current. A certain amount of current is used at all times due to transistor leakage. When one of the radios is on, it requires current. Current is just a measure of how much charge is moving. (It's the rate of change of charge).

    So the current varies depending on what the phone is doing.

    Now, a mAH is essentially a measure of how many hours the battery can supply 1/1000 of an Amp before it dies. In other words, if you have a 1000mAH battery, it can supply 1 Amp for 1 hour before it dies. If asked to produce a half amp, it could do so for 2 hours. In other words, the battery life will be determined based on how much current the phone gets from the battery.

    Essentially voltage has nothing to do with it. (this is an oversimplification, in that batteries are not "ideal" and voltage will vary as the battery depletes, etc.)

    One place people get confused is that microprocessors can have their voltage adjusted to tradeoff speed vs. battery life. The way this works is that if the voltage supplied to the microprocessor is reduced, the current demanded by the microprocessor will also be reduced. Think of it like a flashlight - if you use a smaller battery the light is dimmer. This is because transistors and on-chip wires don't require as much charge to change their state when the voltage is reduced.
    07-11-2007 09:47 AM
  8. marcol's Avatar
    Your own words:

    "My point is that Apple can make a battery that is a mere one quarter the size of the smallest Treo battery last twice as long as the Treo's line of longest performing battery and be driving more things in that time than any Treo every will. You can take that to the bank."

    You say Apple makes batteries...but they don't. (I could ask why you post doo-doo like that, but I already know.)
    You're misunderstanding the sentence you quote. Archie clearly says Apple can make a battery last longer not that Apple makes batteries.
    07-11-2007 10:41 AM
  9. cmaier's Avatar
    Regardless of who makes what, Archie's premise is incorrect. There is no evidence that it is "one quarter the size of the smallest Treo battery," and, in fact, the evidence is that it is at least as large (both physically and in terms of capacity) as a Treo battery.
    07-11-2007 10:47 AM
  10. marcol's Avatar
    iPhone = 3.7V = 300-400mAh
    That's just silly. Look at the pics:




    http://thinksecret.com/archives/iphonetakeapart/

    That's one big slab of battery, significantly bigger than the 1500 mAh battery in my Nokia E61. I'd guess at at least 2500 mAh.
    07-11-2007 10:48 AM
  11. marcol's Avatar
    Regardless of who makes what, Archie's premise is incorrect. There is no evidence that it is "one quarter the size of the smallest Treo battery," and, in fact, the evidence is that it is at least as large (both physically and in terms of capacity) as a Treo battery.
    Agreed
    07-11-2007 10:49 AM
  12. mikec#IM's Avatar
    Regardless of who makes what, Archie's premise is incorrect. There is no evidence that it is "one quarter the size of the smallest Treo battery," and, in fact, the evidence is that it is at least as large (both physically and in terms of capacity) as a Treo battery.
    Bingo.
    07-11-2007 10:55 AM
  13. mikec#IM's Avatar
    That's just silly. Look at the pics:




    http://thinksecret.com/archives/iphonetakeapart/

    That's one big slab of battery, significantly bigger than the 1500 mAh battery in my Nokia E61. I'd guess at at least 2500 mAh.
    Now I think that's the definition of pwned....
    07-11-2007 10:58 AM
  14. archie's Avatar
    Archie - I'm still waiting for a physics lesson where you explain how 3.7V=300-400mAH.
    Well, we can use standy time as a semi dependable constant for current measurement. 250 for the iPhone. 300 for the Treo.

    battery life = mAh rating / current

    That is how I arrived at my admittedly rough estimate.
    07-11-2007 11:50 AM
  15. archie's Avatar
    Hey, Archie, here's a little physics lesson for you. I'll ignore parasitic effects to keep it simple.

    Voltage is a measure of potential (the easiest way to think about it is that a higher voltage between two points means a higher difference in charge between those points). Amps is a measure of current.

    On a battery, ideally, the potential is constant. In this case, 3.7 volts. No matter what the phone is doing, that battery does its best to keep the potential across it's two terminals at 3.7 volts.

    Now, the phone will require a different amount of current depending on what it is doing. If the screen is on, that requires a certain amount of current. Each time the CPU clock transitions, it requires a certain amount of current. Each time a logic gate on the CPU changes state, it requires a certain amount of current. A certain amount of current is used at all times due to transistor leakage. When one of the radios is on, it requires current. Current is just a measure of how much charge is moving. (It's the rate of change of charge).

    So the current varies depending on what the phone is doing.

    Now, a mAH is essentially a measure of how many hours the battery can supply 1/1000 of an Amp before it dies. In other words, if you have a 1000mAH battery, it can supply 1 Amp for 1 hour before it dies. If asked to produce a half amp, it could do so for 2 hours. In other words, the battery life will be determined based on how much current the phone gets from the battery.

    Essentially voltage has nothing to do with it. (this is an oversimplification, in that batteries are not "ideal" and voltage will vary as the battery depletes, etc.)

    One place people get confused is that microprocessors can have their voltage adjusted to tradeoff speed vs. battery life. The way this works is that if the voltage supplied to the microprocessor is reduced, the current demanded by the microprocessor will also be reduced. Think of it like a flashlight - if you use a smaller battery the light is dimmer. This is because transistors and on-chip wires don't require as much charge to change their state when the voltage is reduced.
    I'm no scientist, but this is pretty much my thinking as as well. Thanks for the lesson though.
    07-11-2007 11:54 AM
  16. archie's Avatar
    Archie,

    To quote cmaier, "it's not slander if it's true." And not, I am not slandering you, just repsonding to your posts.

    First, you need to read what you wrote - you said Apple made battteries. (now if that what a mistake, just say so and move on).

    Second, 300-400mah? You have ZERO idea what you are talking about. There is absolutely NO WAY that it's a 300-400mah battery. I will bet a free iPhone to everyone on this thread on that, and better yet, if I am wrong, I will never respond to one of your posts again.

    Are you confusing charge cycles with mah?

    It's common knowledge that in cell phones/smartphones, more mah means longer battery life (yes, voltage plays a factor, but mah is where the rubber meets the road.
    :thumbsdn:
    See marcol's comment above.

    I have more to say on this issue. You'll here it in the very near future.
    07-11-2007 11:56 AM
  17. archie's Avatar
    That's just silly. Look at the pics:




    http://thinksecret.com/archives/iphonetakeapart/

    That's one big slab of battery, significantly bigger than the 1500 mAh battery in my Nokia E61. I'd guess at at least 2500 mAh.
    How can you judge the battery's thickness from these photos?
    07-11-2007 12:02 PM
  18. mikec#IM's Avatar
    How can you judge the battery's thickness from these photos?
    This site has a picture for thickness:

    http://www.ifixit.com/Guide/iPhone
    07-11-2007 12:19 PM
  19. mikec#IM's Avatar
    :thumbsdn:
    See marcol's comment above.

    I have more to say on this issue. You'll here it in the very near future.
    I'm sure I will "here" (sic) about it.

    I've moved beyond that post...I'm more interested in the 300-400 mah battery in the iPhone.
    07-11-2007 12:23 PM
  20. cmaier's Avatar
    Well, we can use standy time as a semi dependable constant for current measurement. 250 for the iPhone. 300 for the Treo.

    battery life = mAh rating / current

    That is how I arrived at my admittedly rough estimate.
    No, you cannot rely on standby time. It is quite easy for two chips which perform identical functions to use completely different amounts of current. For example, compare my alma mater AMD's chips to an Intel chip of similar performance. Even if I used identical circuits, small fabrication changes (different device sizes, doping profiles, metalization approaches, etc.) can result in radically different current consumption. And, increasingly, modern chips are using advanced clocking and power-grid deactivation techniques to reduce current consumption. A chip put in a phone a week ago is going to be very different than a chip put in a phone a year ago.

    The radios could also be operating at completely different power levels.

    Also, you have to look at other functions. The processor is running at 600MHz or so. I think my old treo 650 (with it's 3200mAH extended battery, giving me around the same useful operating time in my brief experience as the iphone) has a processor running around half that.

    Power consumption for a processor will be roughly proportional to the frequency times the square of the voltage. (Note the processor is likely receiving around 1.5 volts, not 3.7). Assuming nearly identical processor design and functionality, therefore, the iphone processor should draw about double the power of the arm processor in my treo 650. (Again, as a processor designer I don't underestimate the ability of good design to affect all this - we had lots of tricks at AMD, but if you're going to do "back of the envelope" calculations, you need to base them on something other than voodoo.)
    07-11-2007 12:28 PM
  21. cmaier's Avatar
    This site has a picture for thickness:

    http://www.ifixit.com/Guide/iPhone
    I don't know if my hands are the same size as the guy in the photos, but I'd estimate that the iphone battery has around 150% of the volume of my treo battery, which would put it at over 5000mAH.
    07-11-2007 12:39 PM
  22. mikec#IM's Avatar
    No, you cannot rely on standby time. It is quite easy for two chips which perform identical functions to use completely different amounts of current. For example, compare my alma mater AMD's chips to an Intel chip of similar performance. Even if I used identical circuits, small fabrication changes (different device sizes, doping profiles, metalization approaches, etc.) can result in radically different current consumption. And, increasingly, modern chips are using advanced clocking and power-grid deactivation techniques to reduce current consumption. A chip put in a phone a week ago is going to be very different than a chip put in a phone a year ago.

    The radios could also be operating at completely different power levels.

    Also, you have to look at other functions. The processor is running at 600MHz or so. I think my old treo 650 (with it's 3200mAH extended battery, giving me around the same useful operating time in my brief experience as the iphone) has a processor running around half that.

    Power consumption for a processor will be roughly proportional to the frequency times the square of the voltage. (Note the processor is likely receiving around 1.5 volts, not 3.7). Assuming nearly identical processor design and functionality, therefore, the iphone processor should draw about double the power of the arm processor in my treo 650. (Again, as a processor designer I don't underestimate the ability of good design to affect all this - we had lots of tricks at AMD, but if you're going to do "back of the envelope" calculations, you need to base them on something other than voodoo.)
    cmaier,

    Good info.

    I now apologize you to for sparring over the battery cycle thing (and the needling comments directed your way as part of that thread). I could blame it on a.) ADD, b.) not being on my meds, or c.) society, but I'm not Paris Hilton, so I'll just buck up and say mea culpa.
    07-11-2007 12:41 PM
  23. cmaier's Avatar
    cmaier,

    Good info.

    I now apologize you to for sparring over the battery cycle thing (and the needling comments directed your way as part of that thread). I could blame it on a.) ADD, b.) not being on my meds, or c.) society, but I'm not Paris Hilton, so I'll just buck up and say mea culpa.
    Ah, the one thing everyone can agree on: Archie is a bit of a loon.
    07-11-2007 12:42 PM
  24. mikec#IM's Avatar
    I don't know if my hands are the same size as the guy in the photos, but I'd estimate that the iphone battery has around 150% of the volume of my treo battery, which would put it at over 5000mAH.
    Yes, that battery is a spicy meatball. I say more in the low to mid 4000 range, but I guess we will wait for the details...
    07-11-2007 12:53 PM
  25. marcol's Avatar
    How can you judge the battery's thickness from these photos?
    I think the second one gives a pretty good idea of thickness. Also if you follow the link you'll see this one:

    07-11-2007 01:34 PM
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