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Solar charging in mobile (cell) phones. Answered

While sitting in the glorious sunshine outside a local pub Sunday on afternoon it struck me that although there are a lot of solar charging options available as add ons I have never seen a phone with solar cells built in.
I could understand it when all the phone companies were making their products smaller & smaller with every new line but now our phones have huge screens the phones are once again getting large & it seems to me that there is a great deal of wasted space that could accommodate strips of solar cells.
My own phone has around 15 square cm of space around the outside alone, added to that there is around 42 square cm of space on the back that could be made use of for something more useful than the manufacturers logo.
I wouldn't expect to dispense with the wall wart altogether but surely it would help to extend the sometimes pitiful life of our mobile technology if it could gather a little energy from the sun.
Any ideas why this isn't being included by the likes of Apple, Samsung & the other manufacturers folks? preferably in terms a non electronics expert can understand :-)


I idly mused about doing it for my Galaxy note, but when I did the maths, a cover the same area of the front and back, made with the best flexible cells I could find, could JUST keep up with the IDLE consumption of the phone.So, to charge it, the phone would have to be switched off. Using crystalline cells, or Gallium arsenide ones (problem: a.) INCREDIBLY expensive and b.) Poisonous), you can pull ahead very, very slowly.

And remember those numbers were based on normal, noon insolation - ie, the stuff we get in the UK once a year.....


Some interesting responses as I had expected.
I see your point Goodhart it wouldn't be much of an advantage for people who tend to keep their phone tucked away when not in use but then many people such as myself & all the people in my home don't, my phone for example sits on my work desk, in a stand by my laptop or in my workshop at least 90% of the day.
Jayefuu's point about durability is a good one, then I don't see that solar cells are any less durable than the screens most smart phones have these days & as for aesthetics while it wouldn't appeal to everyone done right the pattern of the cells could add to the design rather than detract from it.
I concede that leaving a phone in full sun may warm it up a bit sem321, however to be honest  that wouldn't really be necessary & it didn't  seem to the bother people sitting outside my local in 30C sun on Sunday.
Adding solar cells to the back of the phone would be an option if I wanted to mpilchfamily, but as I said in my original post there are plenty of solar charging options available on the market if I wanted to add something I could simply buy one of those, my question was "Why are there no phones on the market that have them?"
Since I posted the question I've had a look around the web, it seems that I was mistaken it has been done & at least one article (which typically I now can't find) claims that the technology is once again being looked into by several of the larger manufacturers.
Here are a few of the examples I found:-





Some of these are several years old & time along with technology has moved on.
The solar cells for example are popping up everywhere, whereas a few years ago a solar charger was a fairly expensive piece of hardware they can now be bought for a few pounds/dollars.
The phones themselves are also very different to those on the market five or six years ago, the drive toward larger screens has brought about changes in materials & construction which I think may lend itself to the incorporation of said solar cells far better than it used to.
Another interesting point came up on my travels around the web,many of the articles mentioned phones that were aimed specifically at people in areas that would not generally have a ready source of power; I imagine that there are many people who lead an active outdoor life who would appreciate a phone that can get at least some energy from the sun without having to plug anything in or add to the things they have to carry around.

I knew it would have come up before it's far to obvious an idea not to.
I think it's one of those ideas that won't really become viable until the technology for the cells, phone hardware & batteries all become energy efficient enough to give a greater payback than currently available.
For certain people however that is less important than simply being able to get some charge out in the sticks when they need to make a call of a few minutes.
Of course there are those of us who only make the occasional call, don't text or BBM every last minute of the day & don't feel the need to publish every second of their lives on social networking sites so the small charge from solar cells each day may be sufficient to cut down their recharging from the wall wart to once or twice a month.
I have a small pocket solar charger/power supply I use in the garden, it powers both my mp3 player & a small set of amplified speakers quite happily all day long, usually the mp3 player is fully charged when I come in at the end of the day.
It has around the same cell area as the available space on my phone so I reckon it would probably keep me going happily for quite a while considering my habit of keeping my phone on the desk rather than in a pocket.
I may see if I can get hold of a micro USB adaptor for it & see how it performs for a week or two.

The phones I have owned in the past, spent much of their time in my hand, mostly "covered" and the rest of the time, in it's little holder around my belt, or in my pocket. This kind of defeats the solar cell.

One reason could be durability. Another could be aesthetics.


5 years ago

Sunlight will also make the mobile hot and thus will require few minutes of cooling before you can put it on your ear.

You could always add your own panel to the back of the phone. But it will add 4mm or 5mm to the thickness of your phone.

One reason you don't see this on phone right now is the added cost. But i think the main reason is how little it actually helps to extend battery life. A small panel like that could only trickle charge the battery. 2 or 3 hours of sun light a day may only give a few extra minutes of run time if even that much. It could be as simple as the inability for the manufacture to put there logo and other information on the body of the phone. You also need to consider how often people actually have the phone out in light levels high enough to effect any charging at all. So its not really a practical addition to the phone. So it better to sell it as an accessory.