This is my guide to convert wired headphones to wireless, without making them bulky and ugly.
Step 1: Get the Materials/items.
What you will need to make the wireless headphones:
1. Wired Headphones.
2. 3.7V LiPo Polymer battery.
3. Bluetooth stereo in-Ear headset.
4. Tactile push button.
5. Female micro USB socket (Or a power connector of your own choice).
6. Thin wires.
7. Soldering iron and solder.
8. Super glue
Headphones: Make sure there are enough space in the headphones for the electronics and battery.
Battery: The capacity depends on how much space you have to work with. I used a small LiPo Polymer battery (around 200 mAh) but i had enough space for a bigger one.
In-Ear headset: You can find these on eBay for around 3 €. I used these
Tactile push button: Can be bought on eBay. Make sure you buy a couple of them in different lenght, you never know what lenght your gonna need for your headphone.
Female micro USB socket: These can also be bought on eBay.
Step 2: Getting Things Ready.
Start with opening the in-Ear headset and locate the antenna, battery (B+,B-), speaker (R+,R-) and power input (5v, ground). In some in-Ear headsets are the power connector soldered to the circuit board, if that's the case then solder it off.
Then cut the wire off your headphones and open up for the speaker on the side where the wire was.
In my case the wire was flat and the hole fit almost perfectly with my female micro USB socket. if this isn´t the case you will have to make a hole for it with either a drill or a knife.
I glued the micro USB with some super glue at the wire hole. I then soldered a red wire to pin 1 on the female micro USB and a black wire to pin 5 (see picture 5 for information Link)
Step 3: Soldering Part 1
The red and black wire from female micro USB solders to V5 and ground on the circuit board.
Then solder the battery, speaker, and the small button off. The button is really small and requires a small soldering iron or a steady hand to get it off without ruining the circuit board.
Then a wire gets soldered on each of the spots where the button once was (There were 3 spots on my case), again this requires a small soldering iron or a steady hand. The wires solders on a button (See picture 4 and 5)
Step 4: Soldering Part 2
Start with soldering the new battery on the circuit board. A 500 mAh battery should keep it running for at least 7-8 hours, but make sure that there is room enough for it.
Solder a red wire to one of the spots on the speaker, and the black on the other (it doesn't matter which one you choose).
I had a little tape package in my headphones which are where the wires split. Unravel this, solder the green wire off the speaker and instead solder the loose wire from the package on.
Then solder the red wire to R+ and black wire on R- on the circuit board.
Test if everything works and that both left and right speaker plays.
Step 5: Almost Done!
I covered the circuit board (but not the antenna) with some tape, so nothing would touch the circuit board. I then drilled a hole in the headphone for the button and glued it in place with some super glue (i had to solder a new button on because the button was too short).
I taped the circuit board and battery to the bottom with some double-sided tape and assemble it all together.
Step 6: Connect and Enjoy!
Connect your new wireless headphones to your smartphone and enjoy!
The quality of the music that the In-Ear Headset delivers surprises me a bit compared to the price and that they weren't originally build to power two speakers. If you listen really well and the music is low (even though the sound is set to high) then it is possible to hear a little buzzing noise, but it´s quite low.
The range is great too (about 10m)
My headphones lasted about 3-4 hours and the capacity of my battery was at about 200 mAh, so a 500 mAh battery is recommended if you plan to use them a whole day.