# GBC Rechargeable mod using a TP4056 module and existing DC Input for charging



## Yrouel (Jan 15, 2020)

Other mods I've seen using similar parts make you cut the case to access the usb port on the TP4056 module to be able to charge the battery however I didn't want to make any irreversible modifications to the case and only minimal alteration to the GBC board also I wanted to use the existing DC Input to charge the battery.

My implementation uses a TP4056 module with the usb port removed and the board trimmed to minimize its footprint, the programming resistor (R3) has also been changed to a 4.7K one and the only modification to the circuit is to remove EM7 which I actually just turned 90° and kept soldered only on one side. This is needed to create a separation between the DC Input and the rest of the circuit where the TP4056 module will be "slipped in".

Here's the schematic of the mod:











The input voltage is taken from the left side of F2 (red wire) and connected to IN+ of the TP4056 module and the output voltage from the module is injected to the right side of F1 (blue wire), the latter is also common to the battery positive which is provided by the existing contact in the battery holder. This arrangement should keep both fuses in circuit to maintain protection.

The negative battery input is taken directly from the battery negative tab via the white wire sneaked in the battery holder (no cuts to the case needed a thin enough wire can pass through the existing hole, the metal contacts need to be removed to pass the wire and can then be replaced).

Ground is common and is connected to the negative of C38 (black wire) simply because is close and the wire can be hidden reasonably well.











The module is secured to the speaker using double sided sticky tape (the thick kind) and oriented with the input side (where the usb port was) toward the right.

This mod uses of only one side of the battery holder so only a single 14500 lithium cell can be fitted, the second spot is occupied by a cut to size nerf dart to avoid accidentally inserting another battery which will likely damage something. This restriction comes from the need to keep this mod as minimally invasive as possible (using the second battery contact is not possible without more modifications).






To charge it I use an USB to 2mm DC barrel jack cable











Useful schematics:


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## FAST6191 (Jan 15, 2020)

Nice one.

Taking bets on how long until you find yourself somewhere where "usb cables everywhere but a nice custom size DC charge jack/universal adapter in sight" is the order of the day.


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## GSPADE (Apr 7, 2020)

Man this is awesome. Exactly what I been looking for. I just did this mod but need to wait for the barrel jack charger to arrive lol So it powers back on all good.

Is it correct there's no wire to the negative in??


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## micp (Apr 7, 2020)

This is super nice. Any idea of how many hours you get out of this?


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## lpoolm (Apr 7, 2020)

Just seen this, also did the same. made a video a while back:


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## GSPADE (Apr 8, 2020)

I can say this didn't work for me. I had to make red wire touch behind the jack with is a positive + connection (instead of F2).

Then even more weird, I made white wire come from + OUT and touch behind the battery negative .

Took a while of messing about and blew a fuse but got there


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## GSPADE (Apr 8, 2020)

lpoolm said:


> Just seen this, also did the same. made a video a while back:




That's cool, but this post is about Not cutting the shell which many tutorials out there do. This is one of the few that do no cut shell and keep as close to factory


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## Jayro (Apr 28, 2020)

You can just solder to the battery terminals on the motherboard, there's no need to overcomplicate this stuff. The GBC takes a 3.7v Li-Ion battery just fine with the TP4056.


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## Griizly (Oct 7, 2020)

I'm willing to do this mod but I don't know which 14500 battery take, I suppose I can take the one with the maximum mAh, i've found some that deliver 2800mAh, is that OK ? 

Is this mod better than simple eneloop pro batteries ?


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## Jayro (Oct 7, 2020)

Griizly said:


> I'm willing to do this mod but I don't know which 14500 battery take, I suppose I can take the one with the maximum mAh, i've found some that deliver 2800mAh, is that OK ?
> 
> Is this mod better than simple eneloop pro batteries ?


Yeah, get the largest mAh you can find to get the most out of it. I just used a 3.7v Kodak camera battery I found on ebay.


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## Griizly (Oct 7, 2020)

Jayro said:


> Yeah, get the largest mAh you can find to get the most out of it. I just used a 3.7v Kodak camera battery I found on ebay.



So as I suppose this single battery is better than 2 eneloop pro at 2500mah ?


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## Jayro (Oct 7, 2020)

Griizly said:


> So as I suppose this single battery is better than 2 eneloop pro at 2500mah ?


That, I'm not sure. The highest capacity I can fit in my Color was 2000mAh, and that's only due to the size constraint of the GBC itself, even after trimming the shell internally. I still get over 6 hours playtime, so I can't complain.


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