UPDATE: Managed to fit a CR2032 in there (the only battery I have on hand) and it seems to work. When I start pokemon, it says the save file is corrupt but it still lets me use the save file (it says it'll use the previous save, but it seems to use the most current one anyway).
Okay, thanks for the info. I opened it up and stuck a LED on the battery, and it still lit up but it was noticeably dimmer than a new CR2032. I don't have my multimeter right now but I'll go ahead and buy a battery anyway.
I have a supercard dsone and an ez flash 3in1 cartridge (phat version). I'm trying to play a hacked version of Pokemon Ruby (Light Platinum) and it refuses to save. I've tried every possible combination of the rom (I've patched it with LIPS/gbata, then tried the sram patcher/clock fix in...