Installing a USB socket

[NiceAft]

I just saw this in BOATUS Magazine. Sorry, but photos don't copy to the Mac site.

Ray


Installing A USB Socket
Story and Photos By John Adey

Make it easier to charge your mobile devices on board by installing a USB outlet.

Photo of a USB socket with phone plugged in
Keeping cell phones, tablets, and other portable electronics topped up is easy
with a USB charging socket installed.

In this day and age, everyone has a mobile device of some sort. But keeping those devices charged up while on the water can be something of a trial. Many boats have a cigarette lighter or a 12-volt plug where it's possible to plug in an adaptor. But the electrical contact is often far from ideal, and I'm not the only boater who's plugged in a phone to charge only to find it flat at the end of the day. A better option is a dedicated, dual-USB socket.

These sockets are a common sight in cars these days, and with the rising use of tablets for navigation and the evolution of decent waterproof/water-resistant cases for phones, USB-charged accessories are now commonplace aboard boats of all sizes. One advantage of the dedicated USB charger is that it's always there, never forgotten, never borrowed. And the USB charger socket, without an adapter protruding beyond the face, presents a very low profile.

Although 3M's 5200 is wonderful stuff, it will make the socket impossible to remove in the future. Use a sealant, such as Dolfinite, that allows for later disassembly.
Installing a charger isn't complicated; you should be able to complete it within two or three hours. To avoid repeated trips to the marine store, think the project through, then go and buy the necessary bits. Right is the list of parts I used to install one on my boat; these parts will work for most similar installations. Pay particular attention to the length of the wire you need. Measure the run of the wire carefully so that you buy enough. It's better to buy a couple of feet too much rather than a few inches too little.

You don't need a lot of specialty tools; you're likely to have most of what you need in the toolbox already. However, investing in a set of ratcheting crimpers will make this, and future jobs, more enjoyable.

The first thing to do is to turn off or, better yet, disconnect the battery. If you have AC circuits on the boat, disconnect these also. To protect you and the boat, there should be nothing live. Don't reconnect the power until you've finished the project. Next, (see photo 1) drill the hole for the socket. I used a spade bit, but a hole saw would be better because it cuts a cleaner hole and creates less dust. The drill bit should be just a little larger than the threaded portion of the USB socket. My bit was a little small, so I had to open out the hole with a rotary tool in my electric drill. Incidentally, this part of the job is a little dusty, so wear goggles, a dust mask, and gloves.

Photo of a drilled hole for USB socketPhoto of taping the wire for the USB socket
Clean up any dust and debris, then run the wire. Allow about 12 inches at the plug end, and tape this to the outside of the hole so it won't be lost as you run the remainder of the wire back to the breaker or fuse panel. Use a wire clip (see photo 2) to support the wire at least every 18 inches from the drilled hole to the circuit-breaker panel. It's OK to use a nylon wire tie to attach the wire to an existing bundle, but aim for a neat and tidy appearance, and make sure that the wire doesn't hang down, where it might get inadvertently snagged. On no account should the wire be attached to throttle lines, gearshift cables, or fuel lines.

When the wire is run, begin the connections. Starting with the source of power, you'll need a positive connection on the switched side of the main breaker, a negative connection to the negative bus bar behind the panel, and overcurrent protection in the form of a fuse (see photo 3). For both the positive and negative connections, use crimp-on ring terminals and heat-shrink tubing. It's extremely important that the ring terminals be the right size for the stud or screw. I hooked up the yellow DC negative via a ring terminal to an open No. 8 screw on the DC negative bus. I connected the red positive to one side of the ATC fuse holder, then hooked up the fuse holder to the switched side of the main-panel board breaker, in this case a quarter-inch stud. I used a butt connector to join the short pigtail on the fuse holder to the wire that runs to the socket.

Photo of a fuse holderPhoto of a ring terminal connection
With the connections made, (see photo 4) I screwed the fuse holder to a wood panel adjacent to the breaker panel. I used a permanent marker to note the size of the fuse I installed so I'll choose the correct size if it ever needs replacing.

When the electrical hookup has been completed at the main panel, turn your attention to the socket. Make the connections to the back of the socket in the same way that you made the connections at the panel, after first trimming the wire to length if it's a little long. But instead of using ring terminals, (see photo 5) use female spade connectors. The back of the socket is marked, (see photo 6) so make sure that the red goes to the positive terminal and the yellow to the negative. Note, too, that you need to slip the threaded ring over the wire on the inside of the panel; this helps hold the socket in place before you make the final connections.

Photo of the USB wire connection detailPhoto of the USB connector detail
Slide the socket into its home, make sure it's straight and level, then drill a couple of pilot holes for the self-tapping screws that come with the plug.

Photo of using a screwdriver to install USB socketPhoto of the final USB socket installation
After adding a bead of suitable mastic under the flanges, (see photo 7) pop the socket back into place and install the screws. Finally tighten up the ring nut on the back of the unit. Clean off any sealant that's squeezed out, then reconnect the power. Make sure all is well by plugging in a phone or other suitable device and determine that it's charging.End of story marker


John Adey is president of the American Boat & Yacht Council.

— Published: December 2015

[Russ]

USB ports are a must these days. I had previously used 12v outlet adapters. Always in the way.

I installed a dual port on the pedestal and a dual in the cabin. Works great to plug phone or pad into while in the cockpit. Watch movies on iPad and keep it charged.

--Russ

[Ixneigh]

Hmmm. I might have to add a few.
Thanks for the write up.
Ix

[81venture]

I have two A/C outlets in the cabin

the one closest to the stern has two built in USB charge ports in the middle of the A/C plugs

Got it at Home Depot

works well... so if you already have shore power and A/C outlet just swap one out with this newer style

[C Buchs]

I try not to keep the adapters at home plugged in because they constantly draw power. I've thought about replacing the cigarette lighter sockets in my cars with a USB outlet. I was looking at this one: http://www.autotoys.com/x/product.php?productid=30318 It also has an auxiliary jack built into the same plug so that I can play music/podcasts from my phone. Does anyone know if these draw power even when something isn’t plugged into it?

Jeff

[shrektruck]

Question asked to the link posted. FWIW-I have a craftsman friend who builds terrapin Teardrops (trailers) he ordered USB ports and unbeknownst to him they had small LEDs under the cover to show power available. Enough to draw down a battery when the trailer is stored (improperly) for a couple months.
Shouldn't be any draw on a USB port with nothing plugged in but I can't verify that for sure. Wall warts still draw power and a USB port spec is 5v so there has to be a step down transformer in the device which may mean a power leak depending on the setup.
Shouldn't be anything huge if your battery is properly maintained.

[C Buchs]

I did some research on the draw of an unused plug. The consensus is that it's less than 5mA. Although I never saw a post from someone who actually measured it. I think I’m worrying about something that is very, very small. I’ll go back to trying to fix the leaks and the stove.

Jeff