What would you do if your cell phone is running out of power. You need it on, but there’s not a power outlet in sight. The answer is simple, If you’ve got a charger and USB cable to spare, you can make your own cell phone charger in 15 minutes! The method works with most phones that have a 3.6 Volt Li-ion battery (this is usually mentioned on the battery itself), but still may not work with some, so make sure it’s a spare charger you’re using.
Most phones will work for this trick but there are supposedly cell phones out there that wouldn’t work— requiring greater current than the USB port can deliver—but these should be very few, and you’d be really unlucky to have ended up with one.
know the USB
The two extremes (pins 4 and 1from left to right) are the ones I am after—they’re the negative and positive terminals for USB power respectively. Pins 2 and 3 are for data.
Hack ‘Em Up
Use a wire cutter or just a blade to cut and open up both the charger and USB cable. The red and black wires in the USB cable are what we’re concerned with—the white and green are for data, so don’t bother with those. Your charger should have red and black wires too—I know of none that wouldn’t have the colour-coding, but you never know.
Making Ends Meet
You’ve probably guessed this now—join the two red wires and the two black wires. If you have access to one, use a soldering iron and secure the connections using solder. This will keep it intact even if you use it a bit roughly. Insulate them from each other using electrical tape (extremely important), and you’re done!
Voila! It works! The next time you have a battery emergency, just leech power off your laptop and make that all important call!