This was an interesting little device, released only in Japan. The unit came with a controller/interface (I believed), that plugged into controller port 2, which was attached to the unit that scanned the barcodes. The controller/interface had an LCD screen, and some buttons I do not know what they do.

The idea was, you took barcodes off various products, anything with a UPC barcode, placed them on cards that come with the unit, and run them through the barcode reader. Based on the information in the barcodes scanned, your players would be given various attributes. Using these attributes, a battle would take place between the two players. From what I have read, this accessory, originally released for the GameBoy, was very popular in Japan. There was even a run on a soup (in Japan) who's barcode was rumored to give a player amazing power.

I should note this device is in no way related to a toy released in the US, by Ertyl, called the Barcode Battler. This toy works like the devices in Japan, but is a standalone handheld system, and is not made by the same manufacturer as the accessories for the SNES and GB.

Recently, xensyria wrote in with the following info:

Your site contains information on the Barcode Battler SNES Add on. You
also said that if anyone had any more information, then to email you.
Well, I belive that what you call the "Super Barcode Battler" is in
fact the "Barcode Battler II" - released in Japan, and in the
US/Europe as the "Barcode Battler" - the original Barcode Battler in
Japan was white, with black buttons, and didn't have the output port
that "Barcode Battler II" had. The US/European versions had this port
- but said in the manual not for use in the UK (in my instruction
book) obviously for the UK.
The Barcode Battler II was (I think) designed for use with the Famicom
originally (the game Barcode World included a cable to link to it),
and so an adaptor (Maybe from the Barcode Battler Senki Super Famicom
Game, or possibly sold seperatlely or with the console), was needed to
link in to the Super Famicom.
As a stand alone console in itself, I am not sure how it would link in
with the Super Famicom, and so I don't know what the buttons would do
in relation to the SNES, but they are used in game for the console.
I think that as all it was used for (I think) for the Super Famicom
was to scan barcodes, then it always outputted to the port every time
a barcode was scanned.

Games for the Barcode Battler:

• Super Warrior Combat
• Barcode Battler Senki: Conveni Wars
• Doroman (planned, released ?)

Here in the U.S., we only got a few brief articles written about it. If anyone knows anything more about this device, let me know.

Source: EGM Magazine #44

Info and pics ripped from EGM, additional info courtesy xensyria