Thanks for the inspirational links! But all those things are huge! My personal goal is to fit all of my power making stuff in EDC kit (on-body EDC!). So the primary criteria for me is how thick it is. Anything more than 3/4 inch (2cm) thick - is not acceptable!

38mm thick solar panel (Explorer)??? Mine is 6 times larger in square inches but only 3mm thick folded with the same footprint!

The explorer solar panel is a dissapointment compared to other folding weather proofed panels such as the panel made by Sunlinq or even your own panel. The Explorer solar panel certainly looks rubust enough though. What I do like is the actual Powermonkey Explorer itself. The charge display panel is a great idea. What I would look for is a 12V to 5V high effieciency convertor to link a Sunlinq panel to the Powermonkey Explorer. The Powermonkey Explorer device is actually not that bulky or heavy in comparision to other similar sized universal Lithium Ion batteries although the form factor is probably dictated by the cylindical Li-ion cell at its heart. I do find it strange that they don't appear to have an adapter to power the Powermonkey from a 12 car cigarette adapter though.

Its the wide range of Monkeynuts and international mains power adapters which make this a useful device. Monkeynuts can be purchased separately to increase the range of devices which can be supported.

From this discussion, it seems that any source of 5-volt power could be used to recharge the average cell phone battery as long as you knew which contact was which... Three 1.5 volt batteries, a solarcell array, a bunch of lemons, copper pennies and zinc washers...

Now I'm picturing some little LED+variable resistor device that will light and indicate polarities up when you are feeding it 5 volts from some jury-rigged system.

My boss really needs to give me more work.:)

-Blast

You can buy very simple three terminal regulators. LM340-5, 7805, etc. Those are available at radio shack but they require a 2v overhead. You can buy low drop out versions from places such as digikey or mouser which only need a 1v overhead. then you can buy fancy switching regulators that will take a wide range of input + and - the output. Very easy to rig up a power supply with some of these.
Our current phones will charge from USB so I'm somewhat standardized there, could pick up any old computer system board or power supply and get a charge from it.

Umm, what?

-Blast (chemist not electrician)

Hi Blast,

Recharging the cell phone battery directly is not really recommended (i.e removing the cell phone battery and attempting to charge it directly) especially if its lithium ion (could catch fire, better to have a dead cell phone rather than serious burns to the hands). Its better to recharge the cell phone battery using the cell phones internal charging regulator circuitry. This is because the cell phone regulator has the ability to accept a voltage variation. If the specs of the phone specify say 5 volts then it is not unreasonable to allow 10-20% variation i.e 4.5 volts to 5.5 volts (3 Alkalines or 4 NiMh AA cells). Of course this requires knowing something about the phones voltage regulation circuitry and which pins are required to be touched by the red (5V) and black wires (GND). Get it wrong and you could have a dead phone. Getting the appropriate Monkeynut for your phone type will go a long way to not damaging your cell phone.

The 3 terminal regulators such as the 7805 are packaged just like a transistor but it is a fully integrated transistor circuit called a voltage/power regulator. Simply put, if you put 9V on the input electrical terminal you get 5 V on the output terminal. If you put 8V on the input terminal you get 5V on the output terminal. So if you have a variable voltage which varies up and down say from 7V to 12 V you will get a regulated steady 5 V on the output terminal. With a 2V overhead i.e 5V + 2V, the minimum voltage the input termanal will accept to work to provide 5V on the output terminal will be 7V.

One of the simplest voltage regulators is a zener diode.

Thats OK, I'm not an electrician either but I have done some house wiring (a lot of people confuse electrical with electronic, an electrician is the guy that wires your house, he doesn't mess with electronic things).

Those numbers I listed are simple electronic parts which are voltage regulators. You simply connect one pin to ground, one to power in and the other to power out. So you can put in a wide range of input power usually 6 or 7 to 15v and get 5v out. If your going to be trying to feed power into a phone then you should look into voltage regulation so the phone remains a communication device and not a fire starter.

Go to electroids.com or adafruit.com and buy a kit for a USB-based iPod charger, and get a USB recharge cable for your phone. That will take care of regulation and let you get just the parts you need rather than having to buy five or ten or twenty of something you need one or two of.

PM us if you get stuck, a lot of us know the electronics, but these are actually a pretty easy kits. You don't have to know what the individual parts do, just which way they go. Don't solder your fingers. Use good solder. Tin your iron, don't count on it being done right at the factory, and remember to get a solder sucker.

I just stumbled onto this thing, don't know if it works or not...

Carport charger

Looks kinda bulky. And advertised as a rocket science acheivement Same 8 AA holders are a buck for a bucket on eBay ( example ). Just add a car lighter socket and wrap in ductape.