Add a USB Power Outlet in Your Car





Introduction: Add a USB Power Outlet in Your Car

Given the bulky nature of 12volt adapters for vehicles, I decided to integrate a USB power outlet in my 2010 Prius III. Although this mod is specific to my car, it can be applied to many cars, trucks, RV's, boats, ect.

Step 1: Finding a Location for the USB Power Plug

In the 2010 Prius III there is an unused outlet next to the 12volt aux power in the front center console. I disassembled the center console and removed the plastic housing of the blank outlet and the 12volt aux.

Step 2: The USB 12 Volt Car Adapter

I disassembled a Dynex USB power adapter and removed the circuit board from the plastic housing, then removed the 12 volt supply wires. The supply wires were springs and such, and too bulky to reuse.

Step 3: Preparing the Blank Cover

Once the blank cover (plug) is removed, I found it to be filled with a dense lattice of plastic. To fit the USB power circuit in it, a lot of the plastic needed to be cut out. Using an Exacto knife, and a box cutter, I cleared the inside of the cover.

Step 4: Fitting the USB Circuit Board

I used a Dremel tool with a grinding attachment to slim down the USB's circuit board until it slid into the hollowed out cover. Once the fit was right, it was time to make the hole on the face to access the USB plug.

Step 5: Making the Hole for the USB Power

I approximated the center of the USB plug and drilled a tiny hole through the face of the blank accessory plug.

Step 6: Wiring

Once I trimmed the opening, It was time to wire the 12 volt power to the USB adapter. Since the 12 volt accessory was right next to it, I soldered the ground from the USB board to the cigarette adapter, and attached the positive end to a nut on the back.

Step 7: Fixing the LED

The USB board has a 2 color LED to indicate power and charging. I wanted the light to shine behind the USB plug, so I de-soldered the LED and repositioned it to face forward. I had to add some wire to the board to attach the LED, but it was not hard, and could be done by a beginner.

Step 8: Securing the USB Board

After making sure the 12 volt accessory and USB power were working, the package needed to be glued into place to prevent it falling back into the center console. I used a general auto glue that holds tight, but remains slightly flexible.

Step 9: Final Install

I let the glue cure overnight. After testing the power out one more time, I slipped the plastic housing back into place. Nice!



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    55 Discussions

    How do you remove that panel from the Prius!? I can't get it off! I don't even know what it's called to search. I've tried every term I could think of... Please help :-(

    1 reply

    Great idea. I have been wanting to put an extra Power outlet in my wife's car, and I think I will include a couple of Double USB ports as well! One for the front Passengers and a double USB outlet in the back for the Kids' devices! Thanks for the inspiration!

    Wow! What a great way to modify an older vehicle!
    Thank you for the details and careful writing. You've produced a very good 'ible!

    1 reply

    That's great, but it didn't exist when I installed the USB power 5 years ago. It also defeats the purpose of making something yourself. That being said, I would probably just buy something like that if I were to do it over again.

    This is cool and all, but you can just buy USB outlets that are made to either be standalone, or if you remove the base, they fit directly where your 12v outlet is. I got this one at a local auto parts store for $15. it's also 2amps.

    usb outlet.JPG
    1 reply

    great job. don't worry about the spammers, you had a problem and you found a way to fix it yourself. you even inspired me to do the same to my car this weekend.

    any thoughts on how to take one 12V cigarette lighter in a 1988 jeep wrangler, and modify so I can keep the cigarette lighter socket but add 1-2 USB chargers?

    I would recommend a different USB part:

    It is panel mount, so it will look nicer and is self-trimming. It has two USB ports and has leads so you don't need to disassemble or hack the part. It just works.

    Most importantly, it is rated at 2.1A (max you want to go on a 10A 12v circuit is about 3A), so you can charge iPads or charge iPhones 2x faster.

    Holy Crap, what a bunch of haters and nincompoops...

    Awesome Job! I like it! Following you...

    There's no need for a fuse, it is just as protected as it was when the adapter was plugged  in to the socket.

    I don't know about the Prius but my car's cig lighter fuse is rated to 10 amps. My USB power adapter's 1 amp fuse will blow long before the car's 10 amp fuse.

    (BTW, I specifically looked for a circuit-protected USB power adapter. Some have fuses and some have circuit breakers. The biggest surprise was finding several expensive models that have no circuit protection at all. Buyer beware!)

    Considering my car's circuit, adding an in-line fuse to your design costs $5. Better to spend a little for protection than to risk ruining expensive electronics.

    But I guess it's ultimately your choice. Good luck! ;^)

    Yea, I fried a $500 GPS because of that. You made a very good point. Hopefully someone wont make the same mistake I did. Dont assume anything is protected. Its always better to have too much than not enough.

    Most of the USB chargers available today have small SMD resettable fuses which are similar to what is on the arduino boards.

    and the socket is plugged into a fuse. also, if I remember correctly, the USB chargers have built in fuses too...

    the 12v line is fused in the fuse box of the car susualu (unless your cars from the 70's) and the 12v plug has a glass fuse inside the barrel. but another 10amp fuse would be a good aditive for a bit more piece of mind. when doing something like this you should add your own 10amp fuse on positive BEFORE is splits to the 12v plug and the usb to prevent too much current being drawn if your cars 12v line isnt fused, you dont want to pull too much power and cook the wiring loom, could be nasty.

    A 10 amp fuse is way too high for this. Your car may have a 10 amp fuse for the 12 V outlet but your USB device only wants .5 amps or so. If you use a 10 amp fuse you will risk killing your USB device or causing a fire if something happens because a USB device will never need 120 Watts of power.