Power Full
(Click to enlarge)
12V Extension for USB
in our Model 3

Mark D Larsen

As all Tesla owners know, our cars just keep getting better and better, thanks to periodic software updates that improve their features and functions. For example, the recent update v.9 enabled one of the windshield cameras to function as a dashcam that records video clips to a thumb drive inserted into one of the USB slots intended for charging cell phones. In fact, it is also possible to use another thumb drive that contains music or audiobooks in one of those slots, and it will appear as an optional device for playback on the touchscreen.

Of course, adding these new software functions goes beyond the capabilities of the current hardware. With only two USB ports, how can you charge TWO phones (whether or not you have a Jeda wireless charging pad) AND record dashcam video to a thumb drive AND play what’s stored on another thumb drive, all at the same time? Alas, it occurred to me that, if only the Model 3’s 12V cigarette lighter outlet were in the front console, instead of under the armrest, it could solve the problem by providing power for additional USB ports.

I then remembered that, in a sailboat that we used to own, Harried Potter, we had 12V adapters and extensions that allowed the use of several devices simultaneously. I still have those accessories, so perhaps I could use one of the extensions to solve that challenge in our Model 3. Below are annotated photos of the project, but be warned: it involves modifications that are not for the faint of heart.

NOTE: You can click on any of the following photos to enlarge them.

What I needed to do is figure out a way of running the extension wire from the back to the front of the console. After a bit of research on the web, I learned that it is possible to remove the grey molding that runs along both sides of the console. It would therefore be possible to run the wire underneath that molding.

The molding is held in place with clips that snap into a bracket that sports the chrome edging along the side of the console. You need to pry it out from the bottom and then tug on it rather sharply at 9 points along its length to unsnap it. Here it is removed from the bracket.

I flipped it over in this photo to show the 9 clips that snap into the bracket.

And here is a close-up of the 3 clips toward the fattest end of the molding.

The next step is to also remove the bracket secured to the console with several torx screws, easy enough to unscrew —if you have the right tool.

In this photo both the molding and bracket have been removed, and I show how the extension would plug into the 12V outlet, with its wire running to the side of the console.

From there it is simply a matter of stringing the wire along the side of the console toward the front. Note the small rubber bumper for the armrest lid to the side of the wire in this photo: you can slide it out of the slot that houses it by pulling on its small tab.

To make the wire less conspicuous, I decided to run it under the rubber bumper by trimming off with a razor blade about half of its bottom on that side.

Here you can see the result, with the bumper again inserted into its slot and the wire running underneath the trimmed side.

And here you can see it from above, again showing the extension plugged into the 12V outlet.

The next step was to figure out how to string the wire from outside the console back into the front compartment. Here you can see it looped over the section that I chose, far enough from the lid openings, yet forward of their hinges up under the dashboard.

I then took a deep breath and... trimmed off a slot for the wire to fit through with a small hacksaw. It was necessary to make the slot about an inch deep so that the lid over the phone shelf wouldn’t rub against the wire when opening and closing.

I then reinstalled the bracket with the chrome edging, and you can see the torx screws securing it in place.

When both the bracket and the molding are replaced, the modification is hardly noticeable. This is how the wire looks that runs under the small rubber bumper into the armrest compartment.

When you open the lid over the phone shelf, you barely see just the bit of wire that now runs down into the storage compartment below.

And this is my solution to the problem. I bought a dual USB port adapter to plug into the extension outlet, each port capable of 3.0A of power.

Here you can see the adapter out of the box, ready to be used with the 12V extension.

Here I have plugged the USB cords from the Jeda Pad into its slots and wrapped it and the extra wire together with a velcro strip.

Another part of my solution was to buy a thumb drive adapter to house a 16GB micro SD card with speeds up to 98 MB/second for recording dashcam clips.

And here you can see everything together: the two Jeda USB cords are in the dual adapter in the 12V extension outlet; the thumb drive with the micro SD card is in the left USB port; and there is also a tiny 8GB thumb drive with our Harry Potter audiobooks in the right USB port.

If I ever need Correcaminos’ 12V outlet for other devices, I also have this duplexer that we used in our sailboat.

Indeed, perhaps this 12V device might also prove useful someday, which boasts both a standard plug outlet for powering computers and yet another USB port.

On the touchscreen you can now see that both the dashcam and the thumb drive audiobook are working, and in the photo at the top of the page you can see that both of our phones are also charging on our Jeda Pad from the 12V extension —all at the same time.

The remaining question is: how fast can our phones charge on the Jeda Pad plugged into the 12V extension? I therefore ran this test on my phone using the Amperes app, which showed that 1% of battery charge took 59 seconds at 1092mA. That is twice as fast as in a previous test when the pad was plugged directly into Correcaminos’ USB ports: 119 seconds at 546mA. What’s not to like?

I think that this modification was worth it. We like using our Jeda Pad to charge both our phones wirelessly, yet we want to take advantage of the new dashcam upgrade, and also use thumb drives to listen to playlists. Now we can have all four functions running simultaneously.