GBA Gets Homebrew USB Charging Upgrade

Sure there are pre-made kits to add a rechargeable battery and USB-C compatibility to Nintendo’s venerable Game Boy Advance, but [HorstBaerbel] thought he could throw together something similar for a fraction of the price. Plus, he wouldn’t have to wait on shipping. The end result might not be quite as polished, but it’s certainly impressive for what’s essentially a junk bin build.

The star of the show is the popular TP4056 lithium-ion charger module. [HorstBaerbel] went with the more common micro USB version, but these boards are also available with USB-C should you want to embrace the future. The module fits nicely inside the original battery compartment while while still leaving room for a 1,000 mAh pouch cell. The 4.2 V output of the fully charged battery is a bit too high for the Game Boy’s liking, so he used the forward voltage drop of a diode to bring it down to a more acceptable 3.5 V.

Naturally this does waste a good deal of energy, especially compared to the DC-DC converters used in commercial offerings like the CleanJuice, but it still delivers a respectable seven hours of runtime. The only issue with this modification seems to be that you’ve got just five minutes to save your progress and shut down when the GBA’s low-battery light goes on; but what’s life without a little excitement?

While not nearly extreme as some of the other GBA modifications we’ve seen over the years, this project is yet another example of the seemingly unlimited hacking potential of Nintendo’s iconic Game Boy line.

18 thoughts on “GBA Gets Homebrew USB Charging Upgrade

  1. The slots for the spring locks in the *micro-usb* port are clearly visible, lol. that’s micro USB

    I recently bought one of those USB-C variants, didn’t test it yet but I bet it’ll be pretty useful. I even put one of those micro-usb tp4056 boards on my an8008 multimeter

  2. I wonder if an LDO regulator would usefully increase battery life (set to emit whatever’s the maximum that the GBA will accept), or if regardless of the diode you’re just running into LiIon’s end-of-charge voltage collapse.

    I also wonder if you’re overdischarging the LiIon pouch. The eBay listing mentions overvoltage and overcurrent protection, but doesn’t explicitly call out undervoltage protection.

      1. No. The battery will discharge much lower than that with this setup. The low voltage cutoff on a GBA is under 2 volts (but most AAs won’t supply the needed current below about 2v) so when you account for the diode dropping the battery voltage, the low voltage cutoff on the TP4056 module will usually kick in first. This is a terrible mod to do if you regularly fully drain the batteries in a GBA. I’ve tested this exact setup before.

        1. You’re right that the GBA shuts off at ~1.9V (I just measured it), which would relate to ~2.6V at the battery. Indeed 3V would be better! The DW01 on the charger board should kick in at 2.4V (typ.), so indeed it would be the GBA cutting power. The battery claims to have an over-charge and -discharge protection though, so I think I’m safe… I’ll measure the voltage the GBA shuts down at again (I remember it to be ’round 3.2V), just to be sure and note on my blog that a over-discharge circuit is recommended.

          1. Have you actually measured this in use? I have. The battery will drop lower than 3v with this setup and that’s very detrimental to battery health, especially if not recharged immediately.

  3. I’m disappointed to see cleanjuice get a recommendation when there are much better mods that don’t rely upon misinformation for sales. A much better mod would be the one RetroModding offers.

    Regarding the misinformation, go ahead and click the link and read the description about how the mod offers more than three times the power available in AA batteries (6.3 “watts” for the mod vs 2 “watts” for “the largest AAs available”). Aside from the units still being wrong (which I have reached out to them about — they ignored me) that is simply not true. W = V*A so 3.7v * 1700mAh is indeed 6.29 watt-hours but go ahead and look at AA batteries too. A common brand NiMh rechargeable is 2450mAh per cell (GBA takes two) so 2450mAh * 1.2v * 2 = 5.88 watt-hours. A far cry from “three times” the power. And this is just on paper. In the real world, the capacity of the LiPo batteries tends to test lower than rated and the capacity of the AAs tends to test higher than rated. Additionally, the efficiency losses due to DC->DC conversion on the LiPo mod actually make the “popular NiMh rechargeable” outlast the cleanjuice in terms of actual runtime.

      1. I don’t know what you want me to say. Supporting a product that lies about specs is not a good alternative to an actual good mod that won’t ship to you.

        The cheapest and longest lasting option is still a quality set of NiMh rechargeables.

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