Everyone knows how to charge a cell phone, even 2 year olds and old people.  Just plug in the rectangle part of the cord into a USB port and wait!  The exciting part of today’s experimental adventure was making a contraption that is actually useful out of my purple battery mountain.  Sure, I proved already that I could charge a small laptop, but I didn’t get the fulfillment I really craved out of charging that piece of shit.

Charging phones from lithium ion 18650 batteries is nothing new, anyone with one of those little power boxes in their pocket basically already has what I made in this experiment – but what they don’t have – is this cool story.  Lets rewind a bit, last week I ordered some cheap USB buck converters from eBay that I wasn’t even sure were going to work at all.  When they finally came in the mail I was excited, and quickly grabbed my fire extinguisher without a second thought.

For testing purposes, I used a couple of those alligator clip wires to clamp onto the PCB input pads and connect them to the battery.  I used a fancy 1998 vintage USB cable that I previously cut off the end for an external phone battery charger.  I plugged the modified cable into the buck converter and used a voltmeter to perform a little quality control inspection before I plugged in a $700 phone.

The tests went well and I finally decided to solder 2 of these buggers in parallel and glue them to a block of wood that I found in my back yard.  Now I am able to charge 2 phones at the same time!  They charge at a decent speed, they claim 3 amps, but I only saw around 1.5 amps each during my test and they were starting to get a little warm.  Overall I’m impressed with these little units from eBay considering they were only $1 and will be using them on upcoming projects also.