I've seen ideas about putting solar cells on cell phones, but there are at least 2 problems (that I can think of right off the bat):
1) a solar panel that small won't draw in enough power.
2) if the phone's in a case or in the shadow of the brim of your hat, it won't get any charge either way.
My solution is to have a hat with a larger solar panel on the brim, with a retractable charging cord (you can lock it with any level of slack you want, like a tape-measure) that plugs into your phone to charge while you're on the go. Even if it doesn't provide enough power to give unlimited talk time, it'll supplement the battery power for increased talk time, and it'll also charge while it's not in use.
(my case, at least, has a small button-up flap at the bottom so you can get a plug into it while it's in the case, but the flap's small enough to prevent the phone from falling out).-- 21 Quest, Nov 10 2006 http://windupradio.com/isun.htm Just add a retractable cord and... voila! [21 Quest, Nov 11 2006] New flexible solar cells http://news.com.com...1398_3-6130312.htmlFrom the article: "We can make it in a T-shirt logo if you want," Terry Schuyler, vice president of sales and marketing at rival CIGS manufacturer DayStar Technologies, joked in a recent interview. [NoOneYouKnow, Nov 11 2006] Cell Phone Bike Charger http://www.halfbake...ne_20Bike_20Charger [21 Quest, Nov 11 2006] Solio Solar Charger http://store.androi...aign=GoogleProductsClick on the picture to see it opened up. [21 Quest, Apr 06 2009] What I like about this is that you can take your hat off and park it in a sunny window while you're inside. This would allow you to continue charging the phone. Also, it can allow you to go on long expeditions in the back country while keeping your phone on just in case. Bunhood.-- wylie_coyote, Nov 10 2006 Would this make the hat kinda heavy?-- Chefboyrbored, Nov 11 2006 Slightly, perhaps. I've got a few cell phone wall chargers lying around, and a couple of them are quite lightweight. I see this being about the same size as the Bluetooth/mp3 player on the RAZRWIRE sunglasses.
If this is too awkward for some having all the weight on one side, no problem. To balance the weight, you could simply have the actual charger on one side, and the retractable cord housing on the other side, with a connecting cord running along the inside of the hat inside the band.
Balanced weight will also mean your hat is that much easier to keep on while driving with your windows open :-)-- 21 Quest, Nov 11 2006 In a similar vein, I recently saw reference to a new material to make the solar cell from that's very flexible. The manufacturers were commenting in the article you could make on into a t-shirt logo. That would serve a similar purpose to your hat. I will attach a link.-- NoOneYouKnow, Nov 11 2006 I would like to see this on a bike helmet. Even if there isn't enough power to charge a phone battery it should be enough to keep the integrated bluetooth headset away from an AC outlet.-- matman, Nov 11 2006 I have an idea posted here for a bike charger, matman. Take a look (link provided).-- 21 Quest, Nov 11 2006 This is a very good idea.-- Alex Yeh, Nov 13 2006 I was shopping around for accessories for my new phone, the HTC G1, and found a solar charger for it (see link), so my idea is now somewhat baked, although it's still not on a hat, and the cord isn't retractable. Kinda neat to find something like that when just over 2 years ago we were wishing for it. As you can see, the total solar surface area isn't much bigger, if any, than the brim of a baseball cap, so my idea would work at least as well as this. If you did this with a wide-brimmed hat, it would probably work at least twice as well as the charger in the link.-- 21 Quest, Apr 06 2009 //a solar panel that small won't draw in enough power//
Not with the Solar Sombrero.-- ldischler, Jun 04 2009 I have a Blackjack and a solar panel 2.5x2.5" will provide enough power to offset the standby drain and fully charge the battery in 1 day iff the phone is off, so I dont know where u get the idea solar wont be enough power.-- Arcanus, Jun 05 2009 random, halfbakery