CR2025
Tensão nominal 3V
Capacidade nominal 160mAh
Peso 2.4g
Diâmetro：20.0mm
Altura： 2.5mm
Most battery-backed GB/GBC games
CR2032
Tensão nominal 3V
Capacidade nominal 220mAh
Peso 3.2g
Diâmetro：20.0mm
Altura： 3.2mm
Nintendo 64 and SNES Game Pak
CR1616
Some battery-backed GB/GBC games
Battery-backed GBA games
All USA GB/GBC Pokémon games have a CR2025 except Pokémon Yellow, which (for some reason) uses a CR1616
In all regions, Pokémon Ruby, Sapphire, and Emerald use a CR1616
battery in the Dreamcast is a 3V ML2032 and so should be replaced with an ML2032. I've seen a fair few people replacing it with an LIR2032, which is a 3.6V Lithium Ion cell with completely different characteristics. The LIR2032 needs a protection circuit (which the Dreamcast lacks as it's not designed to be used with Lithium Ion cells) and so the Dreamcast will discharge it well below its safe cut-off discharge voltage, and the Dreamcast will not be able to charge it properly either.
