How to Make a Rechargeable USB Battery (solar Edition)

where can i find a solar cell

Oh, okay. Thanks, I'm sort of a newbie to this. :P

The answer is no to both your questions. The mAh value is only for duration, it's the volts that are critical. USB is 5V, so 9V is too much, 2AA is 3V, so that is too low.

Would this work with a 9v battery? Even if it did does the equipment you used have to be a certain kind?

Ok, thanks for all of your help.

I will give you a tip. Usually you can find diagrams for any cable/interface that shows all the contacts and their functions. Your brother's suggestion is good, always experiment with parts that you already know work, then once you have figured out the right wires, polarity, etc. then you can go from there. BTW iPhone requires a LOT of power, it's possible that a small charger like this will not be of much use. You will have to do more research.

Ok, one more question. I have an iPhone, and if you've ever cut open one of apple's charging cables, it has a lot more than it needs to charge in it. I assume the extra cables are for syncing your phone with your computer, but I'm really not sure. I really don't want to risk breaking my phone, so my brother suggested that I connect the positive and negative wires to the prongs of the wall charger. That would work, but I'd have a lot of excess cable laying around...

It was just a spare I had laying around from an old solar motor kit. You can get them at most toy stores, or if all else fails, Radio Shack. I can't tell you the voltage since it depends on the light exposure. However, with a small panel like this you would be lucky to get peak 5V.

each battery is 1000 mAh - notice the "h" it stands for 'hours' - this is mA discharged over time with the device drawing however much it needs. In other words it does not discharge all 4000 mA at once so the answer is no. USB only draws 500mA - hence the 500mA rated diode.

and don't you need a 5V 5000mA diode if you have 4.8V 4000mA batteries?

Where did you get your solar panel and how many volts is it?

Normally you would be right. However the two 9V clips used in the rough draft reverse the polarity. Once I completed the circuit I reversed the diode for the final solder. I've tested it several times now and it works great, although it does take a few days to recharge.

Your diode is connected wrong way around.
Cathode to the batteries and Anode to the Solar Cell is the Correct way to do it.
In your connection Sunlight can't charge the batteries because the diode prevents it.

It doesn't work that way. Once the NiMH becomes saturated with electrons the batteries stop charging. Maybe with a huge solar panel you might be able to cause an explosion, but with one this small it's simply impossible.

what about when the panel charges the batteries to much and they explode how do we pravent that?