Someone asked me this. I would imagine it’s because they ussually stay in one’s pocket most of the time, and the time it DOES get some sun, the energy would be too little to matter.
Also what about Ipads and such?
Solar cells are expensive. They also take up a lot of space, which would mean putting them on the back, where there isn’t much light.
You can buy solar chargers for them, if you like.
Really!? The person that asked me seemed to take some pride in thinking up the idea. I guess he was beaten to it.
Where would you put a solar cell on an iPad? On the back, which is going to be facing your lap or a table top most of the time? On the front, where it would decrease the space available for the screen?
Rather than trying to build a solar cell into each cell phone, what is being made is a stand alone cell, with a multi-device chargers.
This one also includes the ability to charge 2 AA batteries, or to use 2 AA batteries that already have a charge, to charge your gizmo.
I think it would be hard to make work from a practical standpoint. Where would the cells go? The front is usually all display with just a small border. The back has more space but gets much less light. There’s also the matter of heat. People may lay the device in a sunny spot to create charge, but then the electronics could overheat.
Solar cells don’t provide much charge. Devices like the iPad want a 1amp charger, which is a lot. So even if they had cells, it might be like trying to fill a bucket with an eye dropper.
That would be my guess.
Cost wouldn’t be a factor since you can buy solar calcualtors for $3 now. Space wouldn’t be a factor either since they could be built into the frame of an ipad under the glass.
I’d guess you just can’t draw enough power from a small solar cell to make it worth it.
there are backpacks and computer bags with a clear window pocket to put a solar charged battery pack into.
You mean like this one?
It’s coming at some point:
http://www.pcworld.com/article/198093/apple_designs_solarpowered_iphones.html
The difference in power requirements between a calculator and something like an iPad are huge you know. A $3 solar panel wouldn’t power anything on the iPad.
There was a cartoon in Sunday’s Parade magazine abouit precisely this. It showed a man wearing a solar panel on his head, and complaining about his solar-powered iPhone.
It’d be wortbh calculating how big an area you’d need, but most people, even if they needed an area as big as that, might be able to put out a charger in their office window*
*assuming they had a window, and a sunward-facing one. I have, at times, had one.
There was some research to a shoe powered recharger, as you walk the compression of the soul produced a good amount of power, far more practical in gaining energy then a solar panel on back of a cell phone, though awkward to use.
What we need is a fabric based flexible solar ‘panel’ that can be dyed and made into a coat or other clothes with a rechargeable pocket to put cell phones and other devices, made in a way that doesn’t require attaching wires.
The display alone is a huge difference, from a non-lit LCD display to a very bright AMOLED (organic LED) display.
You could call it the “Charger of Perpetual Damnation."
There are a lot of solar chargers out there for phones, but generally they don’t work well because of a few reasons:
- PV technology itself isn’t all that efficient yet. Your average cell phone might have a 1500 mAh battery at 3.7 volts. Let’s round that off and call it 5 watt-hours (instead of 5.5). Looking at some sample PV efficiencies, I’m going to round down a little bit and say that the average PV cell technology gets you something like 10 watts a square foot.
Now that doesn’t sound so bad (half an hour to full charge under ideal conditions), but 1 square foot is a huge PV charger for daily use. How and when would you carry that on your person? The “typical” pocket charger (like Solios), last time I checked, put out no more than about 1 watt. That means that in perfect conditions, a pocket charger would take 5 hours to charge your cell phone.
They do sell big portable, foldable panels for more generating capacity for extending camping trips, but the idea is that you’d leave it at camp and let your electronics (or a battery pack) sit there and charge for a long time.
In other words, you just need a lot more square footage than most people are willing to lug around daily. (The technology is improving and there’s a lot on the horizon, but not yet accessible to the mass market)
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It’s really hard to get maximum exposure. Depending on the particular PV technology used, even partial shade can substantially decrease power output. I’m talking clouds in the sky, your head (if you’re wearing it), overhead trees, mountains, being indoors through a window, etc. all decrease your PV charger’s effectiveness, and when you only have 1W max capacity to start with, you don’t have a lot of wiggle room.
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People like to use their devices during the day and charge at night, which is of course counter to what the sun does. Some manufacturers work around this by including a battery pack in the charger, charging that during the day, and using that to charge your device at night.
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Even the cheap chargers are like $60+, and for shorter trips it often just makes more sense to buy an additional battery, pre-charge that and bring it with you. Much simpler, much more reliable.
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As for stationary indoor use, having a large-area PV charger just to charge your phone probably doesn’t make sense on either a financial level (electricity doesn’t cost that much when you have access to it) or a life-cycle analysis, energy-payback level (will the energy spent in manufacturing and distributing the charger ever get paid back through its expected use?). I haven’t done the math to make sure, but that’s what I suspect…
Previous thread: Why Don’t Cell Phones Have Solar Batter Chargers Installed?
And, at least tangentially, Why do they put solar panels on calculators?
I know right! They’ve got solar-powered robots traipsing around Mars whose “cell phones” have a hell of a long-distance plan.
T’row us a bone he’ah!
because, other than Lady Gaga, the general public don’t wanna where their iPhone on their heads.
I wonder if they could put cell phone rechargers on the spinning bikes at the gym. People might execise longer to get their phones charged.