Instructables
today more and more smartphones support wireless charging, whether it's out-of-the-box or via an available hardware upgrade (special back cover). but there is no reason why all other USB charged devices shouldn't enjoy the luxury of wireless charging.

in this instructable i'll show you how to add wireless charging capabilities to your smartphone (demonstrated on a Samsung Galaxy S II) or practically any USB charged device (of course i can't guarantee that it'll work on any device but i see no reason it shouldn't, unless there's some other patent or technology preventing it).

 
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Step 1: Background and clarifications

Picture of background and clarifications
*** FOLLOW THESE INSTRUCTIONS AT YOUR OWN RISK ***
take safety precautions and do not do anything you are not certain of.
i cannot be held responsible to any damage you may cause to your device or to yourself !

(now, after i covered my ass, we can begin)

there are a few projects similar to this one on the net. I've drawn ideas from everywhere and incorporated some of my own.

the whole concept and basic design is based on Palm's technology (although there are other manufacturers offering similar solutions). the Touchstone is a Palm charging dock meant for the Palm Pre smartphone, which supports wireless charging via a separately sold back cover.

there are a few wireless charging technologies made by different manufacturers that all rely on the same physical concept but they are not cross-compatible, you cannot mix coils and docks (I've tried).

i will not bore you with the physics behind the concept (although it's quite interesting) and there's nothing i can write that's not already available with more professional descriptions on the net, so if you want you can google "wireless charging" and read all about it.

Step 2: Gather the components

the components and tool needed for the job :

1. a Palm Touchstone - about 15$ on Ebay
2. a charging coil - about 8.50$ on Ebay
3
. adhesive copper foil
4. a small piece of thin gauge wire
5. a >1000mA USB charger (doesn't have to be original Palm but the cheep chinese ones don't seem to work, i'm working with a 2.1A iPad charger) and USB cable.
6. a case \ back cover \ extended battery cover (w\o extended battery)
7. soldering iron and soldering accessories
8. multimeter (we'll need the volt meter and continuity meter in particular)
9. screwdriver that fits the screws on your device.
10. insulating tape
11. wire stripper and cutter

Step 3: See that everything works and make mods if necessary

Picture of see that everything works and make mods if necessary
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before you start dissecting your phone make sure the components you got work.

first plug the touchstone to the charger and place the coil on top of it with the metal sticker on top of the coil.
measure the voltage between the contact points of the coil, you should get between 5.2v and 5.5V.
this doesn't mean that your phone will charge - there's a trick (this was a piece of information that was hard to find) :
the touchstone apparently only works with "fast charge" capable chargers. the indicator for this is a short between the 2 and 3 pins of the USB cable (the + and - data pins) so make sure your charger can supply more than 1000mA and you'll need to sacrifice a USB cable for this - take a USB cable and remove it's outer insulation leaving the wires intact. (no need to cut the cable although its fine too)
cut the green and white wires and expose their tip. twist them together and solder (this needs to be done only on the touchstone side, no need to shorten both sides)
close everything up with tape

note that the cable is much more delicate now, you might rip it if you yank it.

note also that some chargers just wont work (I tried with a 1$ chinese charger that's rated at 1000mA and it just wont charge - while direct connection to the phone works perfectly) try and use quality chargers, for your battery's sake too.

see the photos for a detailed pinout of the USB port, it can also be helpful in the next steps as i will not refer to specific pins but to their use (ground and +5v in particular)

Step 4: Know your device

Picture of know your device
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disassemble your device carefully (if you're not sure, there are a lot of disassembly tutorials for almost every device out there) and identify the +5V lead on the USB port and follow it to a comfortably solderable spot (unless you are super skilled and equipped and can solder a single micro USB pin) don't worry about the ground lead, every piece of metal in there is grounded.

in my case (galaxy s II), disassembly wasn't hard, 7 screws and a pry tool \ pick \ fingernail and it's open.

finding a place to solder was a little more challanging, it needs to be a place with enough room for the wire and not too small and delicate for the soldering iron to burn or damage.
i used the capacitor shown in the pictures (i had a little help from google and a multimeter finding it).

after you found your soldering spot, try and find the best path for your lead, it has to connect the + from the coil to the + on the USB.

in my case. i chose to work with copper foil because there's just no room for a wire running along the side and the copper foil is relatively easy to work with.

the main consideration for me when choosing the path was that i wanted the phone to seem (almost) unaltered from the outside and for all the separate parts to stay separate (i didn't want a wire or something permanently connecting the board and the cover).

finding ground : 
pretty much every piece of exposed metal should be grounded.
you can check with a continuity meter to see whether a specific piece is grounded or not.
it does not matter what it is you're connecting to, as long as it's connected to ground.
choose the piece that will make your design as simple and as neat as possible.
if no grounded piece of metal can be found you can connect to the USB port ground pin.

Step 5: Choose your weapon

the choice of conductive material is crucial. not so for performance but for your device to close properly. smartphones and electronic devices in general get more and more compact with more and more technology inside, which means less "free" space. that is our main challenge.

because of this i recommend using adhesive copper foil, i found that the adhesive is quite strong but non-conductive (duh..) so just placing one piece on top of another is not enough to close the circuit. that means there are two ways to go :
1. doing it all with one long piece. this method is harder because you need to carefully fold and flatten the foil without layering too much foil and without tearing the foil, which i found was pretty delicate.
2. using multiple pieces and soldering them together. while this method might be a little easier and doesn't require super fine motor skills you still need to be careful not to use too much solder and not to heat the area too much and melt your device.

of course you can use thin gauge wire if it fits.

using copper foil creates another problem - it doesn't have any insulation. my solution is just using insulation tape. one layer shouldn't be too thick. you can cut the insulation tape to shape and choose what area you want to cover (something that is much harder when using insulated wire.

Step 6: Start taping (or wiring)

you can see from the photos that my system consists of 3 separate parts that together connect the leads. i did that because, as i mentioned earlier, i wanted all separate parts to stay separate.
on the device itself - a wire connects the + on the USB (via the ceramic capacitor you can see in the photo) to a copper foil that serves as the contact for the next part.
on the back housing - a (single) copper foil running from the top of the speaker (that is the contact that connects the former part) to the top right corner of the battery compartment - this is the only part visible outside the device and this will be the contact for the next part.
on the back cover - a couple of copper foils running from the leads of the charging coil to their corresponding contact points (the piece of foil sticking out of the battery compartment and a grounded plate which holds the SIM card in place - that's our ground)

it really doesn't matter how you do it, just make sure the device closes back properly and that you are not shortening any circuits.

Step 7: Plan A - fitting the coil under the back cover

plan A implies that there's a plan B. well, there is.
i decided to show you this failed attempt at fitting the charging coil and its circuit under the battery cover because it might be relevant to other devices and even the same one with the extended battery cover.

it appears there is just no space whatsoever between the battery and the cover, not even for the coils circuitry.

placing the charging coil isn't that complicated, just make sure there's room where you place it and that you do not shorten any circuits (the coil and its circuit are fully exposed.

the more complicated part was placing the little metal discs correctly - i came up with an easy solution :
take the cover and coil and place them on the magnetic dock.
the coil might not magnetize well but it should be enough for it not to move too much.
now take the metal discs and place them at the four corners around the coil, they will jump into place thanks to the magnets in the dock.
move the cover around so everything is aligned correctly - the discs should slide on the cover and stay in the same place relatively to the dock. see that the coil is centered between the discs.
take the metal sticker that came with the coil and place it on top of the coil (crucial for it to work)
hold the discs in place with insulating tape.

now you can remove the back cover from the dock and use the copper foil to close the circuit and make the contacts.

Step 8: Plan B - discarding the battery cover and using a simple case

well, plan A went up in smoke, unfortunately. (i wanted to use an aluminium bumper as protection for my phone but that means using the original back cover)

plan B is using a plastic case without the battery cover. this is not ideal (especially with the case i chose) but it works.
if i could find the galaxy s II extended battery back cover (without the battery) for sale that would bring us back to plan A (if you know where i can get one - please share)

well the attempt at plan A did most of the work for plan B, because everything is held together with tape i can just peel it off and move it to the case.
the only thing left is to make sure there's contact. the case has more space between it and the phone (when the back cover is removed), that means more space between the contact points.
what i did to address this was to fold some copper foil and solder it to the contact point to fill the gap. this was not enough so i just filled the remaining gap with solder. (see photo)

Step 9: Close everything up and troubleshoot

close everything and try to charge.

if it's charging - your done.

if not; try these steps : 
1. if there's no sign of charge check your contacts. make sure you have a closed circuit. use a continuity meter.
2. if the charging sign is turning on and off there might be a problem with the charger or the cable, try different chargers or check the cable mod.
3. if your wiring passed under or over any components that also have contact points (like the speaker on my galaxy S II) check that they work, you might have created a gap between the contacts - that's what happened to me with the speaker, opened the phone up and bent the contact springs outwards slightly with a flat screwdriver. works perfectly now.
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brenbart6 months ago

I have a Velocity Micro Cruz tablet someone gave me with a bad usb port. (not positive of the model) I've tried taking it places to have it repaired but they say they can't get parts for it and although I would have expected a USB port to be a standard item, I was told there are literally thousands of different types. I've tried scavenging ports from a few different devices but haven't found one similar enough to work and they seem nearly impossible to remove intact.

Anyway, stupid question about soldering points... I don't see anything on the board that looks like somewhere that I could solder into near the usb port. The battery has wires that plug into a socket on the board. Is there a reason I couldn't splice directly into the battery wires themselves?

harari (author)  brenbart6 months ago

yes, there is. the battery charges through a special charging circuit that regulates voltage and cuts power when the battery is full. it also helps calibrate the battery. it's not healthy to charge the battery directly

This is true, although it isn't just unhealthy to charge the battery directly, it can be incredibly dangerous in the case of lithium batteries. Without the charging circuit to control the current and switch it from bulk to trickle charge, the battery will overcharge, heat up, and can violently explode. Soldering directly to the battery terminals for an extended time can have the same effect.

tankiller55510 months ago
If I use one piece of wire, instead of using adhesive copper foil, will that connect to the 5V or the Ground on the charging coil?
harari (author)  tankiller55510 months ago
As I mentioned in Step 5, the type of conductive material is not important. you can use wire instead of foil. the wire will connect to the 5V lead. the ground lead is the SIM card guard (or any other grounded piece of metal)
DELETED_weard811 months ago
(removed by author or community request)
harari (author)  DELETED_weard811 months ago
lets not start that one..
*sigh...
slaborde1 year ago
Hi,
I have tried to modify a USB cable to short the white and green wires. then I connect it to the touchstone. How to check whether the problem comes from touchstone or chargin coil ?
harari (author)  slaborde1 year ago
first, the shortened side should go in the touchstone.
second, hook the phone directly to the charger without the touchstone to see that the charger is working.
third, check whether the charger is rated at at least 1A.
fourth, do you have a voltmeter? check the voltage between the contacts of the coil (when placed correctly on the touchstone). what do you read? a little voltage or none at all?
Hi harari,
the shortened side is on touchstone side indeed.
I did not put directly the micro usb connector to the phone but I have checked with a voltmeter the voltage between pins 1 & 5 and there is 5.2V as expected.
The charger is rated 2A.
When I put the coil on the touchstone, i read sth like 100mV only... :-(
I don't know if problem comes from coil or touchstone actually.
harari (author)  slaborde1 year ago
hmm.. when i had this kind of problem it was the USB cable that wasn't modded correctly.. try to re-mod it or try another cable.
badview081 year ago
I read your instructions and I had a question of since the Galaxy SII and Note i717 have the same charging port and build structuring but the Note has a 2500 mAh battery instead of a 1650 mAh battery I know that it possibly could increase the charge time. But my question is since you modified the charging structure of the device
1. how has it effected the battery life of the device
2. has the mod degraded battery performance from a users point of view?
3. Are you still using this mod or did you revert back to the original charging circuit.

I have a Galaxy Note i717 and the charge port has gone bad and stumbled across this posting and in addition to buying a new port for the device, I am thinking of doing this mod to mine as I am tired of my charging issue currently. Thanks!
harari (author)  badview081 year ago
I haven't really changed anything in the charging circuitry of the device, just sort of "split" the USB port to allow auxiliary power input.
1. It hasn't. and there's no reason for it to effect battery life. the voltage and amperage is the same.
2. see 1. the mod is completely transparent to the device. it provides the same electrical characteristics as a normal USB charger
3. yes, I'm still using the mod and it's working flawlessly. In fact, i bought another touchstone so i now have one by my bed and one on my desk.
roeyvi191 year ago
אלוף!!
גאווה ישראלית!
harari (author)  roeyvi191 year ago
חח תודה!
rollinns1 year ago
Great work, I have an S2 Skyrocket (AT&T)I'd like to try this on.
Does the NFC (near field communication) still work after this mod?
If I buy a pixi that powers up with a cracked screen (comes with the charger), that powers up, do I still need to buy a coil, or can I use the coil and magnets from the broken pixi?
montalli1 year ago
Hey, very nice assembling! Very clean.
I tried to something like that, but not as clean, as I used a micro-usb connector instead of opening my cellphone case because I have a Motorola Razr HD, with does not allow access to the battery. The problem is, it just doesn't recognize the charger. I shorted pins 2 and 3 on the connector, but nothing. I am using an Qi charger, not cheap chinese, and the voltage I measured is fine. Have you got any ideas what may be wrong? Thanks and congrats again!
harari (author)  montalli1 year ago
i haven't tried using QI so i'm not sure.
i don't even know if shortening the data pins is necessary.
if you measured correct voltage it should charge, have you tried using it on another device?
what's your power source?
Hey. I have redone all my connections and now it is working. I really don't know why, but it does. Now I have to get myself a case and that's it. Thanks for the incentive!
matys2921 year ago
Can u tell which android version or template do you use? It's clean and i love it. And nice project very usefull i will try it in future. Thanks :)
harari (author)  matys2921 year ago
i'm using OmegaROM 4.2.2 AOKP and GO Launcher.
they are both highly customizable.
i like my phone clean and organized, you should see my app drawer, everything is divided into categorized folders. no app icons. -that's the biggest advantage of the GO Launcher over all the others, the app drawer folders (at least for me).
i'll post some screenshots if you want.
i hate these things, they just aren't wireless chargers, do people not understand the concept of wires, In fact this is worse than wires because should you want to use the device whilst charging you will have to use it whilst on the charging base unlike a wired device that you simply pick up.

Would you call your mobile wireless communication if you had to hold it to a wired in wall to make a phone call, would you call your computer mouse wireless if it only worked on a specific mat and nothing else
there is a battery still attached, so yes, it is still a "mobile" device. also, if you notice, he didnt remove the charging port. he simply created a double input of power. he can charge it with a cable, or on the dock. but, for the sake of all the others imagine this:

You walk into your house, after a hard day at work. all you want is rest, but your phone is about to die from all the phone calls you were doing all day. great, now you're gonna have to spend 10 minutes looking for the charger cord. and when you find one, it's not the right size. there goes 10 more minutes. oh, that's right. you remember that you had a dandy wireless charger installed in your house. the wires encompass your whole house, so there is nothing to worry about. you look at your phone, go to settings, press a button, and voila! your phone is charging, no cords, no hassle. you may now rant about how much you need wires.

PS: this idea is a system that I'm working on with a couple friends, maybe ill make an instructable about it.
PSS: thank you for the 'Ible! this helps so much! :D
i understand wireless charging, but gain this is not that,, you have to place your phone on a device wired to a plug socket to charge
If you remove your phone it stops charging

Your concept which is that same s my concept but on a smaller scale involves all or majority of the house fitted with inductance loops in the walls that will wirelessly transmit the power to receiver coils in phones and tv's and computers and blenders etc, but it is very inefficient.
my harge is always in the same place.
You also forgot about ow not all wireless chargers are cross compatible, you get home you place your phone down yu walk off, when you come back you see smoke and your fried phone because you put it on the wrong charging mat
What, no Bluetooth headset?
jongscx1 year ago
I had bought an "extended battery" with a custom backplate for my Samsung Captivate Glide. Because the new battery is twice as wide as the original, I couldn't use the factory back plate.
If you wanted extra space for gadgets to add to your phone, you can't beat these. They're molded rather well and feel comparable to the factory cover, but I'm pretty sure I could fit 3 packs of gum in the extra space provided... I'm actually working on a built in IR module so my phone has an always-attached universal remote. Plenty of space.
The 3 packs of gum example only works if you use the "extended battery cover" and the stock, flatter battery. with the new battery, maybe it's like "1 pack of gum, taken out of the wrapper, squished into random nooks..."
harari (author)  jongscx1 year ago
yeah i'm still looking for a 2000mAh battery cover for sale without the battery but i cant find any.
legless harari1 year ago
The standard battery in my SG2 is a 2000mAh one and I just bought a standard replacement Samsung back for it on ebay when the Telstra branded one cracked.
harari (author)  legless1 year ago
which version do you have? the standard ones (like mine) come with a 1650mAh battery and some versions come with 1800mAh or 1850mAh. the 2000mAh battery for the i9100 is bigger than the original.
i'm pretty sure i've got one here somewhere. mint condition, not in use anymore
harari (author)  lpdunwell1 year ago
and are you willing to spare it or are you just teasing? ;)
kilofeenix1 year ago
http://pages.ebay.com/link/?nav=item.view&id=181096664924 looks like you have the att gs2 this should be the case for you
harari (author)  kilofeenix1 year ago
it's not the at&t version, it's the international (first) version (bought in England).
and the case you suggested is meant for use with a 3500mAh battery which is heavy and ugly. what i'm actually looking for is a back cover (not a case) for the 2000mAh battery which is thicker by about one millimeter. if you come across one of these without a battery please share the link.
kilofeenix1 year ago
http://pages.ebay.com/link/?nav=item.view&id=181096664924 looks like you have the att gs2 this should be the case for you
kilofeenix1 year ago
http://pages.ebay.com/link/?nav=item.view&id=181096664924 looks like you have the att gs2 this should be the case for you
zakgee1 year ago
This may be a dumb question, but could you modify a case, put the components in that, and use a usb cable to connect the phone to the components in the case?
Yeah, but then you'd have that dangly usb bit always hanging out of your charging port. Which would eventually mess up the charging and stuff, as it gets looser.
stefan_gav1 year ago
will this work without disassembly of the phone???(waranty issue)...note 2 has 2 contacts on the back for wireless charging?
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