I recently purchased a XG Flash 2 Turbo flash card after spotting it had an RTC in it. I loaded up Pokemon Emerald and received a message telling me the internal battery was dry. I opened up the cartridge and looked at the (only?) battery. It seems to match this battery (marking say 2020 Panasonic 3V Li) which implies that it's rechargeable. How will the battery charge? I'm leaving it in the slot in my GB Micro while it's on but I'm not sure if I expect that to charge the battery or not, is it simply a case of replacing it?