I bought an Energizer Energi To Go charger to charge up my Palm TX in the field while geocaching. It came with the adapter to charge a Palm as well as one to charge some random cell phone I don't own. It would seem if I wanted to charge my Motorola phone as well I would have to buy another whole Energi To Go unit (or a replacement adapter, see disclaimer below). Not so! Anyone with a bit of soldering ability can mod the extra adapter to accommodate a mini USB plug that will charge a Motorola phone (or virtually anything that can charge from a 5v USB plug).
A special circuit or software is required to force a Motorola phone into charge mode (at least for the model I own). I decided to use the cord from a Motorola charger I got at Goodwill to easily solve that problem. I already had a spare charger that I use in a different part of the house, but the one at Goodwill was only 99 cents, so I picked it up anyway to hack up for this project. If you don't already have one or can't find one at a thrift store, the link here has them for 79 cents (+ a few bucks shipping). These things are everywhere, though. You should be able to get your hands on one if you don't already have an extra one lying around in your closet. But I digress. . . Anyway, the proprietary 'Moto' wall charger has the circuit built into the mini USB plug and therefore solves the problem of getting your phone to actually charge. Here and here are pages including more info about USB pinouts for motorola chargers if you want to make your own.
Disclaimer: I know that you can simply buy an adapter for your Energi To Go unit to power another device, but the ones I've found are $2.99 apiece plus shipping. Also, I like to build my own stuff if I can. If you don't understand this concept you are on the wrong website. ; )
Disclaimer 2: I am also aware of the Minty Boost and am a big fan. If I were really cool I would have made one, but this unit was cheap and here right now--two very powerful aspects in my decision-making process. And besides, this Instructable ties in with another I will be posting soon that uses this same cord. So if you are cooler than me (likely), and you have constructed a Minty Boost, simply substitute the Energi To Go adapter for a standard USB male type A connector instead. And if you bought a Minty Boost, you got nothing on me, so shut it. :p
Okay, I'm done disclaiming. No need for that "don't try this at home" crap.
Step 2: Cut Stuff Up
Cut the wall wart off the Motorola charger. Cut the cell phone plug off the Energi To Go adapter leaving as much wire intact as possible. Strip about 1/4" of insulation off each wire of the Motorola charger. Next strip off an inch or so of the outer insulation of the adapter and 1/4" off the interior wires. Then make sure your heat shrink tubing is handy. I used two different sizes of tubing. The smaller size to separate the wires inside and the larger to go over the whole shebang.
Step 3: Solder Stuff Up
Cut a length of the larger heat shrink tubing that will cover the entire splice and slide it over the USB cord. Cut a smaller piece of thinner tubing and slide it over one of the wires to splice. Solder the first wire and shrink the tubing over it, then solder the second wire and shrink the remaining tubing over the whole thing. Check out the pics below. It's pretty simple stuff.
Step 4: We Be Chargin'
We are done and all is well. The cord looks good and the phone is charging. After scoring a Motorola wall charger at a Goodwill store and already having everything else, this project cost me about 99 cents + tax. All in all, not a bad deal.
[This Instructable is but one piece of a whole. Together with [https://www.instructables.com/id/DIY-Coin-Cell-Holder/ DIY Coin Cell Holder], they combine like Voltron to form one really cool CHDK remote. Check it out: Pocket-Sized CHDK USB Camera Shutter Remote]