From Sega Retro
CR2032 is a designation for a small 3-volt battery about the size of a nickel, very commonly used as the battery for supplying power to SRAM chips to prevent them from losing the stored information when the console is turned off.
- Standard Discharge Current: 0.2 mA, 0.03 mA (BR)
- Maximum discharge current: 3 mA
- Maximum pulse discharge current: 15 mA
It's a very popular battery and in case you ever need to replace an ailing CR2032 they're sold at most electronics stores.
Uses of the CR2032
- Sega Mega Drive cartridges with SRAM backup
- Sega IR 7000 Communicator
- Sega Saturn Internal Backup RAM
- Dreamcast Visual Memory Unit
- Neo Geo Pocket