I received this email and am trying to help them out. If it was for me, I would buy one.
I am a mom of a 7th grade child who lives in NC and is trying to replicate a solar powered iPod charger that someone in the Yosemite Climbing Association built a few years ago. We are desperate to contact the person as we have run into technical difficulties. This person was writing on YosemiteOutside.com if that is any help and has climbed extensively and wrote about it. In their writings, they refer to a clean up and that is how I have come to the two of you as contacts. Again, I am sorry for the intrusion but if either of you have children, you know that a mother will travel to the ends of the earth to help their kid, especially with a science fair project that you are trying to keep alive.
Thank you in advance for indulging me! Be well and hope to hear from you!
I would be curious exactly what chip that kit uses. I'd be tempted to hook up in series and also parallel, such that you get the same voltage, a few D batteries to that same kit. Probably get you through a week of surfing Supertopo on El Cap, I'd think, and you're not stuck buying expensive voodoo batteries, nor trying to charge them with a solar panel in the rain.
I still do like the solar panel idea, though. The $25 one above is the same price / watt as Chris's option though, and since he's saying 6 watts is slow, I'm guessing 2 watts would be useless.
EDIT: Looks like a Linear LT1302 regulator. I think for the iPhone, you'd want to make sure you got the -5 version, not the 12. There's something about the 3GS that doesn't like chargers higher than 5V, I think, you'd have to do some homework, but it will reject them. Seems on the website for that project, they mention a 3GS didn't work. No reason for it not to at 5V, IMO, but I'm not certain. Also looks like it's 2V min, 10V max input, so wiring a bunch of D cells to get 3-6V seems like it would be within the design.
I was not really that impressed, it took a lot of tinkering with and was probably more of a pain in the ass. It did, sort of, extend the life of my ipod while I was belaying, and gave me something to futz with at belays which kept me occupied. But I would have rather it worked with less hassle so I could watch the birds =/
What I did not like about it was that it has a battery in it, the solar charges the battery, then you connect your device, push a button and it charges. It doesn't "trickle charge" which is what I was hoping for.