How to power Escort 9500ix with USB

This is is not related to IT but I feel like sharing it.  :)

I have an Escort 9500ix radar detector which is powered by 12v RJ-11 connector.  The stock power cord looks like below:





















When I go travel, I want everything(GPS, camera, cell phone, tablet, radar detector, etc.) to be powered by USB so:
1) I don't have to carry the bulky power adapters. (especially when going through airport security)
2) I can use multi-port USB car charger (see below) instead of occupying a precious 12v cigarette power socket for each device.


I have no problem power the Garmin GPS as it uses standard 5V USB port.  However the Escort 9500ix radar detector uses 12V RJ-11 port.

So what I need is a 5V-to-12V step-up.  I want it to be small and integrated as I don't want to carry different kinds of modules/adapters.  Luckily I found one from eBay which looks like a USB-to-DC cable but with the step-up module built-in.























All I need to do is to cut the 2.1mm DC plug off and crimp a RJ-11 connector on.  Escort uses the two middle pins of the RJ-11 connector for power.  See picture below for pin-out.














The 5v-to-12v step-up cable doesn't necessarily have a consistent color code.  Thus you'll have to use a multi-meter to tell which wire is positive and which one is negative.  Once identified, insert the wires into the correct slot of the RJ-11 connectors.

The final product looks like below.























What if the cable is not long enough?  Easy, get a USB extension cord.












If you don't have a RJ-11 crimper (see below), you may also just cut and strip a regular telephone cord.  Then twist it with the step-up cable.  All you need is a scissors.