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solar panel on back of phone

nickdalzell

nickdalzell

Extreme Android User
Surprised that we haven't seen this yet. we have seen Mophie Juice Packs that give our phones (and iPhones) small supplemental charges but why haven't we seen the Android phone that has a built-in solar panel on its backside? i'm very surprised this hasn't been done yet!
 
+1 on Codegerm...

As far as an alternate method to power a cell phone, I think the kinetic power would be the better option. Sort of like watches and such. That way, when you walk, you're charging your phone. The only problem with this is that you would need something to avoid overcharging it.
 
Codegerm said:
Excess heat would be one reason. Leaving ones cellphone sitting in the sunlight on your dash or car seat is not good for the device.
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Plus many people would end up leaving their phone behind when letting it sit out.

My phone is either in my hand, or in my purse/pocket so it wouldn't ever get charged by sunlight. However charging a phone without electricity would be cool.
 
I think it's a great idea in theory, but the concept of a solar panel on the back of a phone really starts to break down once you get into the maths of it.

From a G+ post I encountered a while back:
So I've seen a few of these concepts for solar charging your phone, including ones that are back covers for your phone. The idea is cool but it will potentially destroy your battery longevity in the long run. I'll explain below (Warning: Maths and numbers ahead).

On a sunny, cloudless summer midday 1000W of solar energy hits the ground every square metre. Let's, for example, have a solar panel hard back casing which will charge your phone (e.g. via pogo pins) on an HTC One.

The area on the back of the HTC One (without covering the camera and antennae) is around 80 cm
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This won't be useful for me. When I'm out and not using my phone, I place it where the sun doesn't shine, in my holster. If I'm at home or at work, I have easy access to chargers.
 
Stuntman said:
This won't be useful for me. When I'm out and not using my phone, I place it where the sun doesn't shine, in my holster. If I'm at home or at work, I have easy access to chargers.
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So it's not convenient for your phone to get 10-12 hours of direct sunlight in exchange for a few hours of talk time? :D
 
codesplice said:
So it's not convenient for your phone to get 10-12 hours of direct sunlight in exchange for a few hours of talk time? :D
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Exactly; however, if you used kinetic energy you tap into a power source that's much more convenient...you doing the things that you do normally. Carry it in your pocket, purse, holster... It's always charging because you're always moving unless you're dead.
 
i'd love it myself, since my phone often resides with its back turned out in the holster and is exposed to daylight most of the time at work. i just hate plugging it in each day. it's a shame Nikola Tesla's wireless charging tech couldn't be expanded upon, where we could say, walk into a room and voila, our phones and such are charging with no wires, no mats, just charging over the air like wifi. When my phone is sitting on a table charging (or on a mat) it's useless. if i pick it up, the charge is interrupted, and i'm just eating away at that last 18-20%. if i leave it alone, i can't use it. a solar panel would extend the life throughout the day for me, being the eco-friendly type, avoid finding an extra outlet at home, and it along with true wireless charging, would make my phone remain usable even while charging.
 
nickdalzell said:
i'd love it myself, since my phone often resides with its back turned out in the holster and is exposed to daylight most of the time at work. i just hate plugging it in each day. it's a shame Nikola Tesla's wireless charging tech couldn't be expanded upon, where we could say, walk into a room and voila, our phones and such are charging with no wires, no mats, just charging over the air like wifi. When my phone is sitting on a table charging (or on a mat) it's useless. if i pick it up, the charge is interrupted, and i'm just eating away at that last 18-20%. if i leave it alone, i can't use it. a solar panel would extend the life throughout the day for me, being the eco-friendly type, avoid finding an extra outlet at home, and it along with true wireless charging, would make my phone remain usable even while charging.
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You want to remain eco-friendly, yet would like to fill you room with high powered electromagnetic radiation? Which is probably what it would take for what you wish to achieve, i.e. walking into a room and your devices are charging wirelessly. Probably would be like walking into a giant microwave oven. :( Your phone would certainly get charged, but it would also "charge" you as well. Maybe in sci-fi we can do it, :D But I don't think it's achievable, practical or safe in real life just yet.


Even wireless charging pads are nowhere near as efficient or eco-friendly as directly wired charging. Really because air and plastic are very poor conductors of magnetism. They do become noticeably warm which is wasted energy.

Thing with solar charging, depending on where you are in the world, all depends on how much sun you get. More than likely wouldn't work too well in the United Kingdom. Solar power is popular in many emerging markets, like Central Africa, especially when mains electricity can be hard to come by. Even where I am many of the remote cell-towers are in fact solar or wind powered. And I can buy solar powered USB charges for quite low cost. As for putting solar panels onto the back of a phone. I never leave my phone on it's back in the sun, it's nearly always in my pocket, I mean someone might steal it. :D ...and I don't use a holster, I'm not a cowboy. ;)
 
i highly doubt anyone could 'feel' 5V of DC even if it's EM. a cellular phone from the 1980s put out a bit more than that to our brains.

However, your concern would be noted if this applied to regular 120V 60Hz single-phase or higher. we'd definitely be baked...and then there would be cake.
 
Wireless charging requires a constantly changing field - in other words, what you get from AC.

A field from DC is just a magnet, doesn't transfer power.

The greater the distance, the greater the power transfer required, the higher the required flux.

Whether the fields in question would be harmful or not comes down to ionizing vs non-ionizing radiation, total field strength and at levels below all of that, whether medical appliances such as pacemakers are involved.

Maybe see http://en.wikipedia.org/wiki/Inductive_charging
 
nickdalzell said:
i highly doubt anyone could 'feel' 5V of DC even if it's EM. a cellular phone from the 1980s put out a bit more than that to our brains.
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Unless you can devise a way of transferring 5V DC through thin air rather than wires, I don't think wireless in room charging is going to happen any time soon....sorry. :p Basically air is an insulator, and as we all know "Ye canna change the laws of physics!" :D We can transfer vast amounts of DC electricity through thin air of course..we've all seen lightning.
 
Natural lightning is DC though isn't it? A large potential difference between negatively charged clouds and a positive potential ground. Lightning strikes, enormous DC surge for a fraction of a second. I know that electric arcs can be DC or AC, especially HV power-lines, although I don't think that charging your phone by electric arc would be particularly desirable. ;) ...would be like something from 1930s Flash Gordon or a Frankenstein movie. LOL
 
A lot of natural lightning is AC, and sets up a wave between the sky and clouds, or cloud to cloud, with frequency components from 20 to 80 MHz.

While the DC component of lightning is very common and quite large, so is the energy transferred by the higher frequency components.

Lightning can go sky to ground, ground to sky, and also start at both and meet in the middle.

I was part of the NASA/USAF Storm Hazards Research Project - we flew an airplane into lightning and measured the AC frequency components and supplemented it with ground measurements of lightning.

What we learned is that lightning can and will do anything it pleases, usually in rich combinations.

I'm not aware of any DC only lightning measurements but because it's lightning I'm sure it it exists.

Ball lightning (very rare but not a myth, I've seen it) is likely a DC only event.

It's all a capacitive discharge, just as you say.

Those are harmful to electronics so I don't imagine a form of it becoming useful as a charging mechanism.

That leaves inductive charging and then we hit the rules about power squaring and distance as well as frequency.
 
codesplice said:
So it's not convenient for your phone to get 10-12 hours of direct sunlight in exchange for a few hours of talk time? :D
Click to expand...

If I'm mobile and not in my car, I keep my phone in my holster. There really is no convenient place on my person where the phone can be exposed to sunlight as I am moving around. Even though I holster my phone with the back facing out, my holster covers up the back of the phone, so sunlight won't shine on it. Even if I use a holster that does not cover up the back, my shirt or jacket will generally cover up the holster.

If I'm not moving around, I'm usually indoors. If I'm indoors and if I'm going to be in a single room for some period of time, I'm likely going to find a power outlet to charge my phone if needed. If I'm somewhere doing sporting activities, I'm either indoors (ice hockey/badminton) or it is evening (my roller hockey is outdoors starting at 8pm) and the sun is rather low in the sky by then.

When I was in school, I used a solar powered calculator in my science courses. The calculator can operation under indoor lighting conditions. It used an LCD display with no back lighting. The solar panel on the calculator is about the size of the bezel on the top or bottom of most smartphones. I don't know how much technology has advanced, but perhaps one day, devices will be power efficient enough to run off the ambient light when the device is taken out of my holster/pocket. We are certainly not there yet.
 
:rofl:

That blimp was in no way a hydrogen fuel cell. Neither are hydrogen weapons.

Know what else contains hydrogen?

Water.

Know what mysterious molecule is played with in a fuel cell?

Water.

Not dangerous.

Or better - orders of magnitude less dangerous than the battery in your cell phone or Chromebook is right now.

If a word out of place is alarming, wait until I release my evil creation -

The clown battery.
 
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