Sega Master System Cartridge Save Battery Voltage

[DatPhosphorGlow]

Going to start playing Phantasy Star, don't want to replace the battery unless necessary.

What's the minimum voltage the 3V battery should put out for reliable save data?

Cheers,

Carthik

[Einzelherz]

If it's the original I'd personally just cough up the $2. It's worth it to not lose a save.