[This is another howto guide in the Apocalypse series.]

This guide will show you how to convert standard AA battery-powered electronics into USB powered. The ubiquity of USB ports allows you to power items via a whole range of methods, including powerbanks, computers, mains plugs, cars, tvs, as well as allowing for remote operation with an arduino or raspberry pi. This technique is also non-destructive, so you don’t have to hack up or solder your electronics.

The guide is specifically for replacing 2x AA batteries in series, which outputs 3v, but could easily be tweaked for other configurations.


- USB power system
- Powering razor through USB
- Installed inside electronics
- Dummy AA batteries
- Swapable voltage convertors


- 2x AAA to AA battery convertors
- 4.5-7V to 3.3V step down convertor
- 2x red male to female jumper wires
- 2x black male to female jumper wires
- spare wire
- spare USB cable
- heatshrink tubing
- 2 pieces of thin metal


- Soldering iron
- Pliers
- Helping hands stand
- Multimeter or continuity tester
- Wire cutters/strippers


1. Take the step down convertor and bend the pins out. Put some heatshrink tubing on the convertor, so that only the pins are sticking out, and mark which end is which.

2. Now take a length of wire, and strip the ends. Stuff it inside one of the AA dummy batteries, then use the continuity tester to see if the electricity is making its way through.

3. Cut and strip the USB cable. Clip off the white and green wires, leaving just the red and black. Strip the ends, solder two jumper wires on, and add heatshrink tubing.

4. The last thing we need to do is solder some metal contacts to the ends of the other jumper wires. Again, add heatshrinking.

Finished. Connect everything together, add the dummy batteries and insert the contacts into your electronics. The female jumper cables make it easy to swap in different battery and voltage combinations.

Plug in the USB cable, and you now have a USB powered device!


Music (with permission):
Stendeck - Voiceless Wishes Flicker In the Shattered Mist