Could the iPhone 5 push Li-Ion batteries to their limit?

Could the iPhone 5 push Li-Ion batteries to their limit?

Summary: While transistor densities have obeyed Moore's law in keep increasing geometrically, this has put pressure on Li-Ion technology which stubbornly refuses to improve.

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As our portable electronic devices become more powerful, the demands they place on the power packs that supply them with energy increases. As Apple continues to to pack more and more technology into smaller and smaller smartphones, the battery is rapidly becoming the feature that will limit what the rumored, next-generation iPhone 5 is capable of doing.

Noam Kedem, VP of marketing for Leyden Energy, a California-based company that makes batteries for a variety of applications, including consumer electronics and electric vehicles, believes that the iPhone 5 will have a much larger battery than any of its predecessors, but that this might not be enough to keep the device's runtime at the same level as that of the current generation hardware.

"The iPhone 5 battery is going to have to be notably bigger than its predecessor," writes Kedem. "Even with the increase in battery’s X and Y dimensions made possible by a larger screen, the result could still be shorter battery life—in terms of run-time per charge, cycle life and calendar life".

The problem, in a nutshell, is that since Li-Ion batteries first became commercially available back in 1991, transistor density in the devices they power has increased by a staggering one thousand fold, but during that time  battery energy density has only increased three fold.

 

 

 

The iPad 3 highlights just what a problem battery technology has become for Apple. This device has a Li-Ion power pack that is 70 percent bigger than that of the iPad 2, yet still offers a shorter runtime. If you want to extend the battery life, you're going to have to accept some trade-offs in terms of what the device can do.

It's clear that Apple is close to hitting a wall as to how much it can squeeze out of current battery technology.

Many -- myself included -- criticized Apple for fitting non-replaceable batteries into the iPhone and iPad. This does give Apple the chance to pack more battery into a device while keeping the size down to a minimum. It removes the need for the battery to have a case and connectors. The modern battery inside a consumer electronics device is little more than a bag of chemicals with a few wires coming out of it. By eliminating the need for the battery to have a hard case, connectors and the like, Apple has been able to shrink down the overall size of the battery, thus get more bang for the buck.

But even this trick only goes so far.

Kedem believes that with the iPhone 5, Apple will have to get even more creative with how it packs the electronics inside the iPhone around the battery, in order to be able to maximize space for the power pack.

On a more positive note, as electronics get smaller and smaller with each generation of iPhone, this leaves more room inside the device to be filled by the battery.

Another enemy of the battery is heat. Not just heat generated by the device when in use, but he heat produced when the device is charged.

"The higher power requirements of the new features in the iPhone 5 will mean faster discharge," writes Kedem. "Consumer impatience requires making charging happen as fast as possible, but the more powerful battery needed in the iPhone 5 will naturally take more time to charge when using the same charger as the earlier iPhones".

If you want a faster charge time, that means a more powerful charger. And a more powerful charger means more heat being produced. "Trying to reduce charge times with a more powerful charger would likely generate even more heat and further shorten battery life," warns Kedem.

Heat is such a problem with batteries that the iPad 3's Li-Ion cells contain heat spreaders to help dissipate this wasted energy and prolong battery life.

It's going to be interesting to see how Apple balances all these factors in the iPhone 5. Will the company sacrifice features for battery life? Will battery life take a hit? Will Apple give in and make a bigger iPhone? Or does Apple still have a few tricks up its sleeve for getting a little more out of the aging Li-Ion technology.

We'll have to wait and see.  

Image source: iFixit.

Topics: iPhone, Apple, iPad, Smartphones, Tablets

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17 comments
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  • Until a New Chemistry is Developed...

    Apple will remain stuck with the same limits other players have to face. The recent products they released (new iPad in particular) proved that Apple batteries don't have better energy density.

    Now, will the iPhone 5 be unveiled with a totally new battery chemistry that would allow Apple to jump over the competition? I doubt it.

    We will likely see better internal components organization (which is already excellent), smaller parts and a bigger battery to cope with the additional energy consumption.

    Nothing magical. Just something clever.
    TheCyberKnight
  • Density Vs On demand current.

    It is possible to obtain very high density but the problem is that the battery then has a characteristic high impedance limiting the amount of current it can deliver. Cell phone use power in widely fluctuating ways (Screen, radios, GPS, camera flash) and when they are all running at once the current demand is high.

    So a battery for modern smartphones needs to be able to deliver current. And there is an inverse relationship of battery density (mAH) vs current. Voltage per cell is defined by the chemistry. The density and current delivery can be defined by the chemistry and construction. An analogous concept are lead-acid batteries designed for UPS backup power which have high density and fairly low current and low leakage, to true deep-cycle, with somewhat higher current and the ability be deeply discharded, to hybrid forms (also known as deep cycle most consumer boat batteries fit this descripton) with higher current and starting automotive and truck batteries with very high current but lower charge density per volume of battery.
    DevGuy_z
  • Density Vs On demand current.

    It is possible to obtain very high density but the problem is that the battery then has a characteristic high impedance limiting the amount of current it can deliver. Cell phone use power in widely fluctuating ways (Screen, radios, GPS, camera flash) and when they are all running at once the current demand is high.

    So a battery for modern smartphones needs to be able to deliver current. And there is an inverse relationship of battery density (mAH) vs current. Voltage per cell is defined by the chemistry. The density and current delivery can be defined by the chemistry and construction. An analogous concept are lead-acid batteries designed for UPS backup power which have high density and fairly low current and low leakage, to true deep-cycle, with somewhat higher current and the ability be deeply discharded, to hybrid forms (also known as deep cycle most consumer boat batteries fit this descripton) with higher current and starting automotive and truck batteries with very high current but lower charge density per volume of battery.
    DevGuy_z
  • Beyond Lithium Ion

    This is good news for fans of electric cars. Nothing drives research and innovation like the promise of big pots of money. The mobile device market is one big pot of money.
    Robert Hahn
    • Engineering Efforts

      With the extreme need for a better battery, it's surprising that companies like Honda, Toyota or Ford have not come up with something better.
      rhonin
      • Greed is good

        What extreme need? They aren't selling those cars. They're putting on a show for the press and the legislators.

        If you really want a better battery, get the guy who smells an order for 100 million pieces from Apple, and forget the guy who is good at getting government grants.
        Robert Hahn
  • EPEAT vs Battery Performance

    Apple has started gluing their batteries into the case - the new, top-end MacBook Pro - and there is a reason for them to do this, even if doing so conflicts with EPEAT recyclability objectives.

    The reason is heat dissipation. By providing a direct mechanical / thermal path from the battery to the external aluminum case, the battery heat is dissipated much better, battery temperatures made lower and battery life extended. The current iPhone 5 roomers show a metal back-case replacing the glass back of the current iPhone. thinner, stronger, and a better heat spreader to dissipate battery heat. I'd bet on the battery being glued down, too.
    z2217
  • Apple uses lithium polymer batteries

    which are different than plain lithium-ion batteries. They also invested heavily on lithium-air battery technology.

    Li-Ion are similar, but different than Li-Poly.
    wackoae
    • And?

      So does my ASUS, my AW, my......
      Sorry, not getting your point.
      Polymer is lighter but has a longer charge time (getting better) and latest versions are really extending cycle counts.
      rhonin
      • I'm guess you don't get the point

        Which is very simple. The article talks about Li-Ion, not Li-Poly. And Li-Ion has more limitation than Li-Poly.

        So the "theory" behind the entire article is completely meaningless when applied to Apple products ... because Apple does not use Li-Ion batteries.
        wackoae
    • Agreed - Apple doesn't use Lithium Ion like the article states.

      Apple has used lithium polymer batteries for all iPads and I believe all iPhones. (maybe not the first one) They use LiPo in the Macbooks as well. It is more stable than Lithium Ion and doesn't need as much protection. They have already pushed battery technology past the limits of Lithium Ion. LiPo was chosen because they can shape it the way they want to. I don't know of any other manufacture that used LiPo. I bet they will follow in Apple's footsteps though.
      mnbytes
      • Asus uses LiPo

        Correction, It looks like Asus does use LiPo on netbooks.
        mnbytes
  • meh

    apple will probably just copy some existing alternative, claim they "innovated" it, and sue anyone who tries to also use it. seems to be all they know how to do.
    aawolfe@...
    • wah

      This sounds like an anti-apple troll whining about apple with nothing to back them up. I'm going to guess you think Google invented Android OS? Or Bill Gates invented Windows? oops, S.S.D.D. Who cares? They all do it. All that matters is what gets put on the market and available for us to use, really.
      Stormborn
  • Have Doubts

    Honestly, every generation the iphone came out they said it had a better life. It may be true, the battery life could be better but the iphones technology and speed also increased tremendously every generation which consumes a lot of battery life. The next iphone might have more battery juice but the technology will also be upgraded. I think Apple doesn't really need to be concerned about improving the battery, but need to work their appliances. They should work on having their appliances use less battery.
    billwillclark
  • Not so much the chips...

    The big power draw in any tablet or smartphone is always the same -- the display. Apple needs a gigantic battery in the iPad 3 largely because the display draws 2.5x the power of the iPad 1/2 display. A bit of that is due to 4x as many transistors (close to 10 million) driving that display, but most is simply that, with the tighter pixel density, there is less transmittance for the backlight.

    Sure, crank a demanding game to full and you'll have higher CPU and GPU draws as well. But the trendency, ad you add CPU cores, shrink dice, and improve power management is for the computing engine to use less power doing the same work.
    Hazydave
    • LTE chip

      Apple was avoiding going with the LTE chip due to its ineffeciency. I believe that this is more drain on the battery than the previous 3G chips. I agree that the screen, etc add to the drain but the 4G/LTE chip probably contributes to the larger battery and less battery life.
      mnbytes