The Wonderswan color has an horrible screen, but good IPS replacements exist and are easy to mount. However, the Wonderdswan power source is very limited with only one AA battery. An IPS screen can drain up to 450 mAh and the console itself around 200 mAh. That is to say, in 3h or so, the single AA becomes empty. It is even worse with a NiMH battery because of the bigger voltage dropdown. I also experienced less than 30 minutes of battery life with a FlashMasta cartridge ! There are some LiPo adapters on the web, but they are really big with ugly 3d printed design. 

So, I decided to build my own LiPo mod which integrates in the console’s shell with few modifications, and the lipo battery is even removable / replaceable without opening the console 🙂

Here is the story of this mod, and hopefully a sort of guide for anyone who would like to do it…

Required material

• A Wonderswan color, but it will probably work on any model
• A soldering iron with a thin tip
• Some adhesive tape
• A small lipo charger board (about 18.2 x 14.5 cm or smaller)
• A 14500 Lipo battery (AA sized)
• Some thin wires
• An XC6210B152MR LDO regulator
• 10 uf and 1 uf 0805 smd capacitors

LDO regulator

I had to build my own tiny (1x1cm) regulator board (jlcpcb.com) so it could fit into the console. It is very simple and just follows the documentation of the XC6210 family :

The gerber, BOM and EasyEDA files can be found on my github : https://github.com/jit06/wonderswanreg.

The LDO regulator was not available for assembly (I guess few people are interested by 1.5V regulators…), so I ordered the board only and soldered the 3 components myself.

• I = Input 1.5 – 6V
• E = Enable pin : must be bridged with the input in order to get any output
• G = Ground
• O = Output 1.48V

LiPo Charger

The LiPo charger I used is very simple one with only a micro USB connector. But even with its small dimensions I had to cut a bit the board’s corners to make it fits correctly inside the Wonderswan:

Charger and regulator assembly

The new “power circuit” is pretty easy to assemble : the output of the charger is wired directly to the regulator input. Note that the EN pin is bridged with the input. This means that the LDO is always enabled, thus the battery will always be discharging a bit even if the console is switched off. I didn’t find a way to add a small switch, and as the battery is easily removable, I can live with it 🙂  

Battery cathode connector

The main concept of this mod is to put a LiPo battery instead of a standard alkalin one. But the LiPo delivers 3 to 4.2v which is way to much for the Wonderswan. The battery cathode connector has been modified so there can’t be any contact with the console anymore. Instead, the battery is connected to the charger / regulator circuit.

Finally, I had to add some solder to the connector because the cathode of my LiPo battery was too flat to touch it.

Mounting in the console

The XC6210B152MR LDO regulator cannot deliver more than 700 mAh. It is perfectly fine for a stock Wonderswan, but mine has an IPS display which drains about 450 mAh. In addition to the console itself, the total power consumption goes over 700 mAh. In that case, the LDO output voltage would drop so much (I measured 0.7V) that the display would stay off.

Fortunately, the IPS display works perfectly fine if wired directly to the LiPo Battery. So I removed the motherboard and desoldered the display’s positive wire to bring it near the new power supply :

  

Then the display’s positive wire has been soldered together with the battery cathode and the LDO input / charger output. The LDO output is then wired to the console positive battery’s connector and the ground is wired to the negative battery connector.

The LiPo charger is placed on the motherboard’s hole and the regulator board goes under the motherboard, on the left of the charger board. I used some adhesive tape so the charger stay in place before closing the shell.

Shell mod

The shell must be cut in order to close the console with the charger board installed. I used a cutter :

Then, the cathode battery connector can be remounted into the battery holder:

Battery mount

The 14500 LiPo battery can now be safely mounted into the AA battery holder. When closed, the mod is almost seamless, we can just see the micro USB port on the bottom.

When the console is plugged, there is now a red light while it is charging, and green one when it is 100% charged :

Tests

Below are some photos of the Wonderswan color working with this LiPo mod. Guilt Gear petit is an original cartridge, but I also tested with my FlashMasta