friendofmegaman
Offline
CA

Hey folks,

I've been thinking to try out the rechargeable mod on MGB. I watched a few videos on the subject, here's a couple:

1. Prime Time Funk Mods: How to LiPo Mod a Gameboy Pocket by Prime Time Funk Modsz
2. The RECHARGEABLE Gameboy Pocket Mod! by JayBoyMod

The typical set up is a low profile rectangular LiPo cell and a TP4056-based charging board with USB (micro or C). This requires trimming away the battery compartment, modifying the shell to accommodate the USB port (which often involves gluing the charging board to the PCB).

I was wondering if there is a cleaner way to do this mod. Specifically I'm wondering about the following:

- Does anything prevent us from re-using the DC in port as the charging port? This way there will be fewer modifications to the shell. It seems like something like this charging board could be used.
- Is there any reason AAA sized LiPo cells won't work? There will be no need for trimming the battery compartment.

Cheers!

Last edited by friendofmegaman (Aug 2, 2021 9:16 pm)

friendofmegaman
Offline
CA

Re. reusing DC-in as charging port. According to the schematic (page 5) , it seems that we could re-route DC jack pin 1 to the charging board (probably by cutting the trace and jumping) and possibly sever pin 3 (as it becomes unnecessary). Update ground connections accordingly.

EDIT. pin 3 should be shorted with pin2 I think actually...

Last edited by friendofmegaman (Aug 2, 2021 5:08 pm)

friendofmegaman
Offline
CA

This article makes a point of using a diode between battery terminal:

The diode [1N4148] is placed between the positive battery terminal and the positive BAT point on the charger or Game Boy positive battery terminal. The purpose of the diode is to drop the voltage about .6 volts and prevent any "reverse charge" from reaching the battery during Game Boy use. Li-Ion/Li-Po batteries are typically 3.7 volts, and with the diode, it comes down to a more friendly 2.8 - 3.1 volts. Game Boys usually run from 3 volts (1.5V + 1.5V, for each AA or AAA). It's possible to run the Game Boy directly from the Li-Ion battery, but it is neither safe nor practical for long-term use.

friendofmegaman
Offline
CA

And here kineticcc did two LiPo's in parallel

Concerns:
- AAA-sized LiPo cells with protective circuits are bigger than regular AAA batteries, hence the shell modification is still required.
- Unprotected batteries do seem to be near perfectly AAA-sized, but they're a fire hazard. Hm...

Further direction of inquiry:
- Consider safer battery technology.

Last edited by friendofmegaman (Aug 2, 2021 9:18 pm)