Why can't we have Solar Powered batteries in iOS Devices?

Discussion in 'iPad' started by Rodster, Jun 24, 2012.

  1. Rodster macrumors 68040

    May 15, 2007
    So Logitech announced solar powered keyboards for the iPad recently that can stay charged for up to 2 years. :eek:

    Why hasn't this battery technology been brought to smartphones be it iOS/Android/Windows Phones as well as Tables like the iPad? How cool would it be not to worry about running out of batteries while using your iPad?

    I can only dream, right? :)
  2. pcomac macrumors regular

    Jun 22, 2011
    because then apple cant make money replacing your battery
  3. ThatsMeRight macrumors 68020

    Sep 12, 2009
    Because there will be people stupid enough to lay them in the full sun. And smartphones don't like extremely high temperatures.

    In Africa, they do have special, cheap dumpphones with batteries that are solar powered.
  4. NewbieCanada macrumors 68030

    Oct 9, 2007
    Two AA batteries last for weeks or months in a keyboard, mouse or trackpad.

    A much larger battery lasts for hours in a smart phone. And that's why you can use a small solar battery to power a device that needs next to now power and can't use one to power something that eats it at an incredible rate.
  5. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    It takes more power to operate an iPad than a keyboard. current solar cells wouldn't provide enough power for the size of the iPad. And where would you put the solar cells? on the back? then what if you use a case?
  6. NewbieCanada macrumors 68030

    Oct 9, 2007
    Solar batteries are no less prone to needing replacements than regular ones. Unless Apple owns shares in power companies it doesn't matter to them what kind of recharging method is used.
  7. Rodster thread starter macrumors 68040

    May 15, 2007
    Yeah but the Logitech keyboards batteries charge while indoors to. They don't have to be outside in direct sunlight. Indoor ambient lighting is sufficient for charging the batteries. The tech is already there. :)
  8. johnmacward macrumors regular


    Jul 12, 2011
    Pretty much bang on, all batteries are now Lithium Polymer or previously Lithium Ion and when this chemical experiences heat it degrades fast. At worst, it gets hotter, expands and explodes. Heat is an enemy of battery technology, then again cold is also an enemy, so a general temperature range between about 7 to 30 degrees is acceptable - unfortunately this puts solar charging out of range.

    Also, consider using your iDevice out in the sun - you wouldn't see the screen and would naturally find some shade - hence negating the effect of charging the damn device.
  9. silverblack, Jun 24, 2012
    Last edited: Jun 24, 2012

    silverblack macrumors 68030


    Nov 27, 2007
    Because an iPad requires a lot more power compared to a keyboard or a calculator. In order to generate enough current to deliver significant charges to the iPad, the solar panel would make the iPad much less portable.

    You can look into 3rd party solar chargers, but they are quite big in size in order to deliver 1-2 amps. By the way, big solar panels = $$$
  10. Rodster thread starter macrumors 68040

    May 15, 2007
    But the Logitech batteries are charged while indoors as well. The tech is getting there.
  11. johnmacward macrumors regular


    Jul 12, 2011
    A keyboard is an unbelievably low power device whereas a full tablet / phone device uses much, much more. Current solar technology cannot deliver a quick enough charge in an indoor environment (or possibly outdoor) to generate enough ongoing current to keep the device alive.

    In time it may possibly happen indeed and it would be great to see it as well, but right now, no.
  12. Piggie macrumors G3


    Feb 23, 2010
    On the other hand life could be extended from all these devices by using some of the heat produced by the circuitry and turning it back into power to charge the batteries.

    I'm sure there are many many ways of turning heat into electricity.
    And let face it, all these gadgets produce a lot of heat, so if that could be harnessed and put back into the battery, whilst it would not recharge them, it would extend the time you would get from a charge.

    Perhaps this will come in time. It is a bit of a "No Brainer" as they say.
  13. eawmp1 macrumors 601


    Feb 19, 2008
    Because it is less advanced battery technology than is already found in the iPhone. Why can you have a solar charged toy car, yet a solar full sized automobile is not practical? Toy cars and keyboards sip energy. Automobiles and iPhones guzzle it.
  14. johnmacward macrumors regular


    Jul 12, 2011
    Nothing that you are saying is wrong technically and all within the knowledge of science. In fact there may be 6 different methods of utilising heat power from a device. But these 6 different methods will take up space, add bulk and add complexity to a device that's already complex enough.

    I'm with you, I'd love to see something like this happen but I assume it's still years away, maybe a good decade or two in fact and also because it's not on companies top list of priorities either.
  15. Jessica Lares macrumors G3

    Jessica Lares

    Oct 31, 2009
    Near Dallas, Texas, USA
    There is no way I'm letting my iPhone or an iPad hang out in the 102/104 F weather in Texas. Solar is great for energy, calculators, and stuff like that. Not for computer hardware. Our iDevices already get hot as they are!
  16. Snowy_River macrumors 68030


    Jul 17, 2002
    Corvallis, OR
    Well, there are some fundamental flaws with this idea. The reality is that somewhere around 10% to 20% of energy used in modern electronics goes into waste heat. So, even if you could recapture all of that and pipe it back into the system, the best you could do would be to increase the effective battery life by about 20%. However, simple physics tells us that you can't have any form of energy conversion that is 100% efficient, so don't expect to get anywhere near that.

    That being said, the conversion of heat into usable energy is something of the Holy Grail for energy physicists and engineers. Currently, there are ways of doing this for large scale heat reservoirs (think of geothermal electricity plants) with the relatively high efficiency rating of 30-35%. Certain new designs that take advantage of extreme high temperature and pressure effects can get up to almost 50% efficiency.

    For small scale thermal reservoirs (i.e. any iDevice, or even something as big as your car, which has a LOT more heat waste issues than any electronic device today), the primary way to convert heat to electricity is through use of the Peltier effect. In this case, this takes advantage of the fact that certain metal alloys, when connected to each other and kept at differing temperatures, will develop a voltage differential between them. Simply put, if you get metal A hot and keep metal B cold, you'll get power. This form of power conversion is limited, though. In cases where you can get fairly high heat differentials, you can get an efficiency of up to about 10%. But in instances when the heat differential is not as significant (think less than 100 degrees C difference between the temperatures of the two plates), the efficiency drops dramatically, even down to the 1%-2% range.

    So, even if you could get a low temperature Peltier generator working with a "high" efficiency of 15% (which would be an incredible break through), you'd be able to recover 15% of the 10% to 20% of energy that goes into waste heat, giving you, at most, a 3% energy recovery. Weigh that against the potential increase in size, weight and cost of an iDevice that has such a heat recovery system. It would make far more sense for the engineers at Apple, at this point, to work toward reducing the amount of energy that gets lost in waste heat, rather than trying to recover it after it's been lost.
  17. HipHopTrex macrumors member

    Mar 9, 2012
    Solar powered recharge stations are practical now, if that makes you feel better. something like this I've owned one of these, they're very very nice and effective. I just let it sit in my window, while the usb cord(And obviously phone) would sit down on my bed.

    Now I think in a few more generations of iphone maybe 3-5. We might see something where if it can stay cooler, while it recharges MAYBE we get something that recharges using solar energy. I think this is bound to happen soon, since no one's been able to reinvent the battery. And while everything else in phones/tablets/laptops/desktops etc etc get smaller, the battery takes up much more space.
  18. Redjericho macrumors 6502a

    Sep 16, 2011
    You wanna pay $3,500 for a 16gb wifi model be my guest.
  19. Piggie macrumors G3


    Feb 23, 2010
    Perhaps if they could fit inside the case a form a kinetic movement recharging system, then every time a guy goes to some porn web sites he could recharge the device.

    Think about it for a bit :D
  20. NT1440 macrumors G4


    May 18, 2008
    That tech powers the extremely low power keyboard, the same tech would take days to charge the iPad.

    Put shortly, the tech isn't here yet.
  21. Fruit Cake macrumors 6502a

    Mar 31, 2012
    I want to charge my solar powered iPad with a solar powered torch!
  22. takeshi74 macrumors 601

    Feb 9, 2011
    The tech isn't getting there for charging devices that consume tremendous amounts of power like smartphones and tablets. There's a reason why you're seeing that tech used in low power devices. People have been pointing out the massive power consumption differences over and over and over in this thread and you keep repeating yourself.

    Compare the power consumption and battery capacities for yourself. Specs for solar cells are available and you can do the math to figure out how practical it is.

    The phrase you're looking for is "pipe dream".
  23. Rodster thread starter macrumors 68040

    May 15, 2007
  24. Cobster macrumors member

    Jun 13, 2011
    Believe it or nor...The whole World does not live on sunny California... :cool:
  25. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    And where would the solar powered device be in high latitudes where days are very short? If you only have 6 hours of daylight, that's not going to help much.

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