Adzetko
Offline
Ardèche, France

Hi everybody, I'm new here!

I am documenting myself about gameboy modding before getting my hands 'dirty' (I currently have 3 DMG-01,  and waiting for one black Play It Loud and 3 pokets that I've bought online), and I've seen some LIPO batteries mods, with USB charger (like this one in gbdev files server: http://gbdev.gg8.se/files/modding/lipo% … 0guide.pdf ).

The thing is:
I was asking myself if this is possible to simply solder a Qi Coil

› like this one

to the charging board.
Can you help me, nice people from the internet? Thanks wink

Category
Offline
South UK

Unsure, never touched Qi. But if the voltage out of the coil during charging is around 3.3v, it should (in theory) work. I'd just buy one and test it out with multimeter in hand. If not, a capacitor may be able to soak it up, and push into the charge circuit at regular intervals. Definitely not outside the realm of possibility

EDIT:- of course, if the current is too low it could take an age to charge

Last edited by Category (May 16, 2015 10:32 pm)

Adzetko
Offline
Ardèche, France

Thank you for your answer! wink I'm waiting for your experiment report, haha ^^
This system is largely used for phones, and take a look at some phones battery (at least for Android phones) and it is generally around 3.7V !

Another problem: a friend of mine (trust him, he is studying in watchmaking, and passionated in old-school electronics) have seen another problem: the possibles interferences between the Qi transmitter and the CPU (and the others chips), it could work as a "fake" reciever. I don't know in detail what he thinks it can do, but if this affects something in the chips, that would not be something good.

Knife Crimes
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Adzetko wrote:

I was asking myself if this is possible to simply solder a Qi Coil to the charging board.

No. The charging board pictured at your first link is USB powered so expects 5V DC. The coil alone will output AC.

There are Qi receiver pads available with USB output, regulated to 5V DC. Try something like that instead.

loudaslife
Offline
Kansas

As Knife Crimes said, there are some nice little self-contained coils with all of the electronics built in for USB output, designed to sit on the back of a smartphone underneath a case. Example.

I think one of those would connect directly to a USB LiPo charger without issue.

You'll have to make sure that the Game Boy can handle up to 4.2v if you're connecting it directly to the battery. That's about the voltage you'll get during charging and for a short time after a full charge with LiPos. The guide you linked does this seemingly without issue, so take that however you will. If you find the Game Boy can't handle this, you'll need a regulator of some sort.

Also, make sure your LiPo has a built in protection board. Almost all of them do, depends on where you buy it though. If it didn't have that protection circuitry, you could accidentally discharge the battery so far it would be ruined. It also usually provides over-current protection, which is nice if you don't want your Game Boy to literally explode in your pocket in the event of a short circuit.

Adzetko
Offline
Ardèche, France

Thank you for your answers! (I'm glad you guys are here, so I am not making explosive gameboys)

loudaslife wrote:

You'll have to make sure that the Game Boy can handle up to 4.2v

The DMG-01 is by default running 4x1.5V batteries (in serial, so it is 6V if I remember good old school days), so it might work, no?

Knife Crimes
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It will work fine, nitro2k01 has the numbers: http://blog.gg8.se/wordpress/2009/07/22 … ge-ranges/