Build a Hidden Qi Wireless Phone Charger!

Phone docks are expensive and platform-specific. Charging cables are annoying and unsightly. Wireless chargers alleviate some of these inconveniences, but still leave a lot of polish to be desired. I set out to eliminate all of these complaints, and in building a wireless charger into a nightstand or desk, I am now able to plop my phone down on my nightstand and watch as the battery fills up - like magic.

For this Instructable, I will be demonstrating the process of building a wireless Qi charger into a desk or nightstand. The results are polished, convenient, and impressive. Done right, you'll make your phone-charging experience seamless and attractive.

Step 1: Supplies

In terms of supplies for the project, you'll need the following parts and tools ready to use. You may have to hunt around to find a MakerSpace with a ShopBot CNC Router, but you could (in theory) chisel out your wood surface instead.

• PowerBot Qi standard induction charger (any color!)
  • I chose the red model knowing that I wanted to use one of the rubber rings to indicate where my charging pad is hidden.
  • This model comes with a USB cable long enough to use for this project!
• Any 5v AC - USB power adapter, 1.5A output or greater works best
  
  • You can use any 5v USB adapter, including the one that came with your phone. A higher output adapter will charge your phone faster.
• Small phillips screwdriver
• Small flathead screwdriver
• Hot glue gun
• Router (CNC or manual)
  • I used a ShopBot, see if your MakerSpace has one!

You'll also need the obvious:

• A desk or nightstand that you're comfortable taking apart and manipulating
  • I used a board of walnut to illustrate my project since my desk is made of glass and my nightstand is ugly.
• A phone that supports induction charging via the Qi standard
  • iPhones are not supported
  • Most Samsung Galaxy phones are supported with a special back cover
    • Example: Samsung Galaxy S4 Qi Battery Cover
  • Many recent Windows Phones and Android Phones support Qi
    • Phones with MicroUSB charging ports that do NOT natively support Qi can use the following adapter to add Qi charging capability using the MicroUSB port
      • MicroUSB Qi Charging Film

Step 2: Disassemble the PowerBot

Dig in! Peel away what you can of the plastic housing with your flathead screwdriver, then pry the rest off. The PowerBot casing is in two halves, you'll need to separate the two. With the PCB exposed (it's screwed into the top half of the casing), use your phillips screwdriver to remove the guts of the PowerBot. What you see in my final picture here is where the magic happens - that's an induction coil you're looking at! Your Qi compatible phone has a similar coil inside it, to receive the electromagnetic field produced by the PowerBot.

The induction charging system can only work within a limited distance. The coil in your phone can't be too far away from the coil from the PowerBot, so removing the PowerBot's casing reduces unnecessary obstruction between the two coils. This will come into play in the next step...

Step 3: Find the Maximum Charging Distance

As you can see in these pictures, I've confirmed that the naked PowerBot is working with my phone, and I've confirmed that the PowerBot continues to charge my phone when the phone is raised above the induction coil. I estimate from this test that it will continue to charge up until around 0.3 inches. If you have a case on your phone, this may be a little tight - you'll definitely need to use a CNC router for better precision. If you keep your phone case-free, you may be able to get away with a hand router (or even a chisel!).

Remember - GREEN means it's charging. RED means there's no connection.

Step 4: Get Your CNC File Ready (for ShopBot Only)

I measured the size of the naked PowerBot, and accounted for the room that the included MicroUSB cable needs. After creating a quick 2D vector in Adobe Illustrator, I imported the vector lines into my school's ShopBot software, figured out how deep I wanted the router to cut (With my 1 inch wood slab, I cut in 0.8 inches. This leaves me with a little over 0.1 inches of wiggle room for charging.), and started the task.

Attached are all the files I used in the process of using the CNC router.

Step 5: Fit and Attach Naked PowerBot

With my included CNC files, your naked PowerBot will fit in just about perfectly! You shouldn't have to use any excessive force sliding the naked PowerBot into the hole, and the MicroUSB cable should fit happily, too. Make sure the MicroUSB cable is plugged in BEFORE sliding the naked PowerBot into place.

After confirming that the naked PowerBot fits and still functions (red light means "Ready to Charge!" in the second picture), use your hot glue gun to (CAREFULLY) glue the naked PowerBot into place. This is key - you don't want your hidden charger falling fate to gravity. I glued in/around the existing screw holes, and my naked PowerBot is held snugly in place. Keep your MicroUSB cable ATTACHED throughout this process, but keep your 5v AC/USB adapter UNPLUGGED from the wall.

Step 6: Flip Your Surface Over and Test!

Success! I drop my phone onto my hidden charger, and immediately it begins to charge. I also hot-glued the red rubber ring from the first step to the top of the surface (desk or table) to indicate where the charger is. You can now reassemble your desk or table, and enjoy your hidden charger!

Comments

[Mickeypedia]

Thanks for this post! I used it as an inspiration for a birthday present for my mom who was complaining about plugging in her cell phone to charge at night. I didn't have access to take her nightstand so I built the wireless charger into a decorative plaque that I stained and engraved with her initials to sit on her nightstand that she can just set her phone on at night to charge. It turned out great and works great!

P.S. Sorry for the poor quality of images (should have used my moms phone, it's nicer than mine lol)

[bobburghart]

Looks stunning! Nice thin design, too!

[TonyB7]

I will be incorporating this into my home bar that I am currently building. I'll post up my pictures on my site and be sure to link to your excellent Instructable and give credit were it is due. Thanks for the great idea.

[bobburghart]

Great use of the concept, can't wait to see your project!

[bobburghart]

I'll be responding to any comments and questions here!

[wonderbrett]

Curious -
with the right tools and metal, would it be possible to make an entire tabletop like this? So regardless of where the phone sits, it would work?

[bilge17]

Great work on this ible...I like the suggestion of recessing the red ring into the top surface also. I have another suggestion, make an clear acrylic ring the same size to fit into the recessed space and drill a tiny hole where the green/red LED is on the Bot unit is below. it will always glow red until you set your phone on it.

[bobburghart]

I like this idea, it keeps the surface flush while still indicating exactly where the wireless charger is. I'm personally not a fan of the LED light being visible (my phone tells me when it's charging), but that's a preference thing.

Unfortunately, I won't be able to make the Illustrator files for the two sized rubber rings (as mentioned in my previous comment here). I used my rubber rings from a knockoff PowerBot I disassembled, and it turns out the rings are not the same size as the genuine PowerBot's rings. I was hasty in my disassembly of the genuine PowerBot and didn't think to save the red rings. Sorry!

[synthdust]

Might be neat to simulate a light coffee/beverage ring to indicate where the charger is instead of an out of place red ring. Just a thought!

[bobburghart]

Of all the "where did I hide my wireless charger?" solutions so far, I like this one best. I'm going to "sticky" your comment so it shows up on top, so others see your idea!

[Anubis256]

Great walk-through on this! Is there any concern with heat from the induction coil on the wood? I know it doesn't get so hot there's a real concern for combustion or anything close to that, but at least in the typical plastic housing, there's vertical space for the heat to dissipate some during and right after charging. In this case, the coil is essentially directly contacting the wood and so negates any heat dissipation. It is somewhat less a safety concern and more a longevity of the charger concern. A full few years in, can you give us some idea of how the set up has fared?

[DamianL28]

Hi, i want to install one charger under my desk. But i'm little afraid that if i leave too less thickness then accidentally i can make a hole in the desk. ive seen the Evoline charger QI that's made for installing in furniture but they said the thickness must be 0,3mm. it's too low! Which thickness u left? Of course ill try by myself which is the max thickness for charging but if its too less anyway, ill not even buy a charger for trying. Thanks

[bobburghart]

I left 0.2" thickness, or approx 5mm of wood remaining. 0.3mm is very thin and I would be very concerned about accidentally damaging the surface of the desk. Consider using an alternate charger, with a greater charging distance like the one I showed in my guide. Hot glue isn't as nice as a threaded solution like the Evoline, but it still works!

[DamianL28]

i dont want evoline, its expensive only because its the only product on the market in his genre. i can have same result with other products, disassembling them (thanks to you). ok so next question will be the most powerful charger? u wrote this article 3 years ago, and now theres a ton of these chargers around, and nowhere in the reviews, is tested the charging distance/range

[bobburghart]

I'm not sure. My guess is that any chargers following the Qi wireless charging standard would have similar distance/range. Select a wireless charger that matches or exceeds the wattage supported for wireless charging your phone. For example, if the iPhone 8 supports 7.5W charging over wireless charging, be sure to purchase a 7.5W or greater wireless charger.

[DamianL28]

ok thanks. ill buy the 15w then, it seems its the max available right now, and i let u know

[MiklosM3]

and how do you make sure not to punch through the board? what are the preventive steps in this matter?

thanks!

[bobburghart]

You set the depth of cut for CNC router, or adjust the router depth for a handheld electric router. I did this in step 4, I used a 0.8" depth of cut for the 1" thick slab of wood to leave 0.2" remaining.

[LeighE5]

This is quite an old guide now, but I'm guessing not much has changed since it was made, except the introduction of Qi to iPhones which will increase it's popularity. I want to do it but don't have access to fancy machines, it'll be a chisel job, does anyone know of a guide to that effect?

[bobburghart]

You could do this with a handheld electric router, instead of a CNC router. Electric routers can be purchased at Home Depot, Lowes, etc.