Solar powered cell phone charger case hack
I'm getting an HTC Evo soon. This phone has a lot of screen real estate. It's going to require a decent sized hip case. Why can't I slap a couple solar panels on the outside of the case with a small USB cable plugged into the phone while it's resting on my belt? I want to take advantage of the size of this thing and have my own hacked solar case.
So here's my idea. I want to grab a couple panels out of some all-weather garden lights. Mount two solar panels to the outside of a good case when I find the right one. Then add a 5V regulator wired to a mini-USB plug. When I put my phone in it's pouch I could just plug the end of the short wire into the phone to charge it, or at least help it keep a charge while I'm out and about without having to worry about carrying around a solar kit to pull out and pay attention to.
The reason I need advice. I don't know much of anything about solar panels other than what I've heard in other DYI tutorials. I'm not an electrician so I don't know much about the power requirements of the phone outside of standard USB voltage.
What would I need for amperage requirements? Is a 5V regulator enough to ensure no damage to the phone? The phone will only pull as much amperage as it needs as far as I understand it. Will the phone safely stop charging when it's full or will I blow up my battery?
I know they make cases for iPhones like this for $80+. I think I can build one for ~$20 save for the actual case itself.
Any help would be appreciated. Thanks
A little bit of clarification on my project. I've looked at a lot of other Instructable projects as well as ones all over Google. I've got a lot of good info from them, and I know I *can* do this, but because I'm trying to charge such an expensive device I want to make sure I have every little detail worked out. I've read warnings about issues with part of a solar cell being in the shade (wasn't detailed on why). With my scope of electrical understanding, I would feel comfortable following these guides if I was doing the exact same project with the same amount of panels, but I'm going to have to change things up a little bit mainly due to space and weight constraints since this is going to be mounted on my hip.
The biggest requirement here is that the panels produce enough power to charge a USB device without having to trickle charge a separate battery first. I won't have the space on my cell phone pouch for an extra mounted battery. The entirety of this device should be no more than the pouch itself, one or two solar panels and a few wires. The main concern here is getting the amperage I need to charge the phone faster than it drains with only one or two panels.
I'm not looking for step by step instruction here, just a bit of advice from someone who knows a thing or two about PV to give me some tips on solar panel size and power. Also any safety precautions I need to take to keep from causing electrical damage to my phone.