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I want to mount a tablet to a wall with a charger but I don't want the charger to be visible. Can I put a normal wall outlet in the INSIDE of the wall and just plug in the charger inside the wall?

Location is Wisconsin, USA.

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  • What do you mean by inside the wall? Recessed? Cover over with some sort of panel?
    – bib
    Commented Jan 21, 2016 at 19:03
  • I mean like actually putting the outlet in the wall, between the two sides of drywall. Not recessed.
    – Programmer
    Commented Jan 21, 2016 at 19:06
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    With just the charger wire sticking out through a hole in the drywall? Commented Jan 21, 2016 at 19:11
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    No, you can't. But you can find mountable receptacles with USB charging ports built in. Google "USB RECEPTACLE" Commented Jan 21, 2016 at 20:50
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    What if that cable breaks, or your new device (or your spouse/friends) doesn't use that kind of connection? IMO, you're best bet is to get an outlet that also has a 2A USB port. Unless you really like to cut/patch holes in the walls, or open/close a panel every time you need to change out the wire. YMMV
    – coblr
    Commented Jan 21, 2016 at 23:54

8 Answers 8

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No. Section 314.29 of the National Electrical Code (adopted in some form in most localities in the US) requires that all outlet boxes be accessible without removing any part of the building or structure. That includes wallboard.

You could build a recessed section in the wall that has an easily removed front panel. You could install an outlet in that section, plug in the charger and then run the charging cable through a hole in that panel.

If the tablet uses a standard USB charger, you can now get outlets that have the charger built in. Then you just need to plug the low voltage USB cable into the outlet and into the tablet.

usb outlet

 Images and links are illustrative only, not an endorsement of goods or sources.
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    National Electrical Code I assume that referers to a specific nation and may not apply all over the rest of the world?
    – njzk2
    Commented Jan 22, 2016 at 3:11
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    I have at least one of these in every room now and they are AWESOME. Kitchen counter, bedroom, by the couch, etc...
    – DrewJordan
    Commented Jan 22, 2016 at 16:09
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    @DrewJordan The only downside is vampire current draw (pretty small). And many of us leave our unused charges plugged in anyway, so the built in is no worse.
    – bib
    Commented Jan 22, 2016 at 16:37
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    @bib: To expand on your answer, "pretty small" is on the order of single-digit milliamps. This works out to something like 1 cent per week per outlet if my math is right. Some usb outlets have a physical shutter on the usb ports that entirely eliminates vampire current. Commented Jan 22, 2016 at 19:22
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    Keeping in mind the issue with many USB-powered devices using many incompatible protocols to identify the charger and even request different voltages. I've listed some in my comment on the question. Having a normal (hidden? recessed?) outlet with a standard charger plugged in lets you swap it out as necessary.
    – Bob
    Commented Jan 23, 2016 at 5:24
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You can use a recessed outlet to hide the wires. These were originally created so wall mounted electrical clocks can be mounted flush. They are now pretty commonly used for home theater setups where the TV is mounted to the wall, so there aren't any visible wires.

Something like this could work for your tablet setup. You would just have to make sure that there is enough room in the box to accommodate it since it leaves much less room for the wires.

Recessed Outlet

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    This is a good option. I didn't mention it because the OP seemed to want the outlet behind the drywall with no charger showing.
    – bib
    Commented Jan 21, 2016 at 20:01
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    @bib fair enough. I think the best solution would be a recessed outlet with the USB charger built right into it. They probably do exist, but I didn't spend a lot of time trying to find one. Commented Jan 21, 2016 at 20:04
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    @bib the question was a clear case of the X-Y Problem Commented Jan 21, 2016 at 21:50
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    @DanNeely Y do you want to keep X-ing out our brilliant solutions? These are answers in search of a question? What part of this game don't you understand? (If you vote for me, I will trade you two secret hats for a blogpost).
    – bib
    Commented Jan 21, 2016 at 22:24
  • This will infuriate the next owner once they want to plug in a power brick, though. :)
    – DA01
    Commented Jan 22, 2016 at 17:21
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I recommend combining a recessed outlet box, outlet with usb charging, and right angle usb cable.

recessed outlet box outlet with usb charging right angle usb cable

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  • Is there a plate available to cover such a box? I'd like to be able to just run a cable into the box through the wall and plug in but still have it accessible. Commented Nov 15, 2022 at 14:55
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As pointed out by many others at this point, direct answer to your question is No: you are not allowed to install an outlet inside a wall. All outlets and junctions must be accessible without having to modify building structure or components.

I would skip the high voltage entirely here and use Power-over-Ethernet (PoE) on Cat5e/6 cables to bring power to the tablet. This avoids the need for extra junction boxes, running 120V wiring, access panels, etc.

It's also very easy to fish Cat5e/6 through as small as 3/8" holes, making it fairly easy to run wherever you need to go. Another future benefit is that it's also relatively easy to tear out (compared to something involving 120V wiring/outlets) if you're moving or want to move or remove the tablet mount.

enter image description here

In your case you don't need the "data" part, so that simply wouldn't be hooked up.

The actual power supply can be anywhere the ethernet cable can reach (up to 100m/328'), ideally out of sight in the basement or with the rest of your network cabling.

The receiving end is just low-voltage, and can sit tucked behind your mount. You'll want it accessible in some way in case it breaks or something, but it doesn't fall under NEC rules.

Cheap/"passive" PoE

The cheapeest way is to just use "passive" PoE, which isn't standardized, but just uses the unused pairs of 10/100 connections for power. Various kits exist, a quick search finds that you may need an adapter to convert the barrel-style DC adapter these usually have to a USB female jack.

enter image description here enter image description here

There's a couple downsides to this: if you connect a regular ethernet device on the other end for some reason, there's a chance it could fry it. Since there are no standards on this, you should only use the pair of injector/splitter from the same source to ensure compatibility.

Some of these kits run power at 5V, so after about 15' you can get some voltage loss which will at some point cease to charge the tablet. Better ones will run at 24 or 48V and do a step-down to 5V output, so they can handle quite a bit of drop.

802.3af/at PoE

You also can go with actual 802.3af/at PoE. This always runs at ~48V to avoid voltage drop, negotiates power requirements (won't fry non-PoE stuff), and is an actual standard that works across manufacturers. If you already have a PoE switch with spare ports for something else or have other PoE stuff to power (eg IP camera or phone), this is probably the best option.

enter image description here enter image description here

You can get 802.3af/at PoE injectors or switchs to provide power.

enter image description here enter image description here

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  • If your solution is basically to run low voltage cable all the way there, why worry at all about Cat5 or (somewhat) expensive PoE injectors? Just run some alarm wire with 5VDC and call it a day.
    – JPhi1618
    Commented Jan 22, 2016 at 16:59
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    @JPhi1618 Because you have to worry about voltage drop. Alarm wire in particular is usually 22 AWG -- after about 15', a 5V source at 1amp will be 4.52V, which is the minimum the USB spec allows for. I know from experience this can have a big effect: with a 10" Tab S connected to a 10' cable and leaving the screen on 24/7, after a few days, it would actually run out of battery. Changing nothing but the cable to a 6' solved this problem. Using off-the-shelf PoE avoids the need for DIY voltage regulator circuitry and/or hacked together cables.
    – gregmac
    Commented Jan 22, 2016 at 17:44
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Can you do it, sure. Should you do it, no way.

  1. If you ever want to sell your house, it probably won't pass inspection if the inspector finds it like that
  2. If your house ever catches fire due to that wiring your homeowners insurance will not cover it.
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As alluded to above, the obvious answer is to get a large clock receptacle (just google it), e.g., http://www.amazon.com/Arlington-DVFR2W-1-Recessed-Electrical-Paintable/dp/B001XQ4JFC -- with this one you can go to town, mount whatever you want in it.

And you'll need a 90 degree micro USB adapter to make the charging cable go away. Ebay has stuff like that.

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I think you are asking the wrong question -- if you are wanting to power a low voltage device with a USB charging connection from AC Mains, then what you want is a transformer or AC/DC converter -- these are NOT outlets and can be mounted out of sight (think doorbell transformers for example).

The fact that you wire it to the device through a usb connector would not be relevant since that is a low voltage connection. Just make sure the converter/transformer is certified for in wall use.

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    OP already has a 'transformer' (the charger). All they need is some additional wire and a low voltage splice any which way they please. +1 for thinking outside the outlet box. They might run into a topographical limit of about 10' though.
    – Mazura
    Commented Jun 25, 2017 at 18:13
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I have resolved this problem with my inwall iPads. I simply have a recessed (in wall) mount that I cut large hole in drywall for, then I install the receptacle in the wall but easily accessible through the iPad mounting hole, then plug in charger, and stick iPad into wall inside the hole. To access the plug, I simply remove the iPad (3 minutes) and reach inside and unplug or plug in the charger, and then re-install the iPad. (3 more minutes)

Since there is no need to modify drywall or any structural part of the house its legal. (my opinion, but I see no problem)

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    Do you have any pictures of the installation?
    – Programmer
    Commented Aug 18, 2017 at 12:35

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