From Bulbapedia, the community-driven Pokémon encyclopedia.
Pokémon Battle e is an addition to the GBA Generation III games. It utilises the e-Reader to add new content to the Pokémon RPGs of that generation.
5 sets have been released in Japan, but only the first has been released in the United States, Canada and Australia.
There are some promotional cards which have been given out at different times in Japan, but only four of the Japanese promos have been released in English, as well as two early version cards that packaged with North American versions of Pokémon Ruby and Sapphire. Please see Pokémon Battle e Promotional cards for a full list.