Induction Charger

[marco]

Hi there,
I'm in the process of building my own gameboy zero.
Thanks to this community I've learned and learned a lot already.

==This is my turn to share some tips on my build.==

Please -check -this -out, I moded the original gameboy battery cover to fit an iphone QI receiver, here it; standing on top of the QI charger:


The battery cover will gently settle on the back of the gameboy, and the QI receiver will be stacekd on top of the LiPo:


As you can see the build is really thin, and compact. Now I have a clean 5V to powerup the charger unit.

Here is how I did that.

First I bought a QI iphone receiver on ebay:

It's ridiculously cheap when ordered from China.

Firstly I made some bench tests and verify it can deliver up to 1A @4.7-5V:


After the bench tests were over, it was time to dissasemble it and make it fit inside the gameboy shell;
Inside the receiver, we can identify three main parts:
1-ribbon connector
2-QI controller board
3-Coil with some magnetic tap on top of it.

To fit in the gameboy battery cover, the ribbon connector must be cut, and QI controller board must be set on top the coil, so connections between controller board and coil must be extended a little bit:




I used some kapton tape because it sticks, it's thin, and it can support high temperature. I was worried the QI controller would heat up and melt the glue if any. As it turns out the controller indeed heat up, but it's not that hot.
The only trick you have to bear in mind in case you would be willing to do the same, is to connect the + with the middle pin so the QI controller see a load and will enable charging.

Also the gambeoy battery cover must be generously trimmed:




I'm gona post some fresh pics of my build this week

[fcib]

Well done! I have a samsung wireless charger already, so maybe I'll check if that uses QI (probably does) and try this in my second build.

My concern is that you said it gets hot and is backing directly onto the battery... Have you had any issues?

[marco]

You have a point here! In my case I've got 3-4mm marging between battery pack and QI receiver module so that should be fine.
Though it could be wise to shield the battery with kapton tape.

[marco]

Hello guys,
here is a complement to the tuto (or sort of...) above.
If like me you are using a TP4056 module to charge you 1S lipo, its' better considering reducing the charging current so it wont draw too much current from the QI receiver.


I changed ground resistor on pin2 from 1K2 to 4k7//4k7 so current sunk on the 5V charger fall from 900mA to a more acceptable 500mA.
According to datasheet this resistor (RPROG) set the charge current:


Here is the mod (I stacked two 0603 4k7 to respect the rating but one 2k would do).