12V to 5V USB Charging in a Camper


I've got a pickup truck camper.  The internal electrical system is 12VDC.  I wanted to be able to recharge my phone and tablet while sleeping.  I wanted to install some 12V sockets in the over-the-cab sleeping area.  Not satisfied with just adding chargers, I decided that I wanted some LED strip lighting in the area too.

This is a photo blog on how I used my Makerbot Replicator2, LED lights from Ikea, and components from Radio Shack & Fry's to make a cool addition to my camper.


Using the now-defunct 3D modeling Web site tinkercad.com, I designed a control plate with spots for a 12V utility socket, some switches, a power indicator LED and a socket into which I could plug LED strip lights:


The 3D print of the control plate took about six hours.  It's already fitted with all the holes that I'll need forthe 12V socket, switches and power indicator.  The hole on the side will be the port into which the the LED strip lights will plug in.


This shows how the 12V socket mounts in the center of the control plate.


I want the wiring to be neat and tidy, so I've gone to the 
trouble of using proper lugs. 


The loops in the wires is a style that I learned long ago: make sure you have enough wire to reach anywhere into your project. You never know when you'll going to rearrange everything, so you don't want the wires to be too short. 


The little LED light that I wanted to use as a power indicator for the 12V socket requires a step down resistor, so I had to do some soldering. 


You'll see in later images that I used shrink tubing on the resistor wire.  While not strictly necessary, I thought it made the project look neater. 


I discovered that the Ikea Ledberg LED strip lights were 12V, I realized that it was an opportunity to for some very inexpensive lighting for the camper.  I started by liberating the end socket from its 120VAC to 12VDC adapter.


Discarding the transformer, I now needed to test to make sure that the +/- labeling on the bottom edge of the socket was to be trusted. 


It was, indeed, properly labeled as I tested a single strip on a 12V battery. 


Wired into the switch, the LED socket was then hot glued into the channel on the underside of the control plate. 


Using a saw on a Leatherman tool, I cut a access into the side panel inside the camper.  Not shown was running a 12VDC power connector into that space, too. 


The control plate dropped into the hole perfectly and, once wired and powered, I demonstrated that the power indicator light worked correctly. 


I then plugged in the 12VDC to 5V USB converter and I suddenly had a way to recharge my phone and tablet on the bedside in the camper.


The LED lights work, too.  I reproduced this in mirror image on the other side of the bed giving me great diffuse lighting and the ability to recharge two phones, and two tablets at the same time.