Hi!
I recently hooked up my Super Nintendo and played Super Metroid. I got quite far and decided to go to bed and continue the next day. When I got up and started up the good ol' SNES again, the screen said "No Data". My saved game was gone and I realized; the battery powering the SRAM was dead.
So I headed to Google, looking up instructions for replacing the battery. Other than buying the battery and opening the cartridge, you also have to desoder the battery, and soder a new one. Making sure I don't damage the battery in the process. And it got me thinking; do I really have to do this every time the battery runs dry? Sure, that doesn't happen that often, the game is 20 years old. But in this process you also loose all your saved data, and thats really sad when you have an old, precious save of Final Fantasy that you don't want to loose.
So I have a couple of ideas of a solution that I think would fit in one episode.
Solution 1:
The simplest of them all would be to add a detachable battery cover where the battery would sit in place so you easily replace it when its time. This however does not solve the issue of loosing data when you change battery. Maybe its possible to make room for two batteries, so when it time to change. So when you put one in and remove the dead battery, so the SRAM still has power. Maybe this could be solved with a capacitor, so if you change the battery quick enough, the circuit would still have charge without any battery. But I don't know about electronics, I'm just a simple programmer. A battery indicator would also nice, so you know when its time.
Solution 2:
Put in a chargeable battery so that you simply can connect a power source and charge it when it's needed. No data would be lost as long as you keep the battery charged. A battery indicator would be needed here also.
Solution 3:
This is the most complicated one that I don't even know if it's possible. Replace the SRAM with some sort of flash storage that wouldn't need a battery. You would probably need some IC:s to convert the data to the pins on the cartridge.. And the IC:s would need power.. Yeah, this might not be possible without coming back to the problem of a external power source.. But it would be fun to see if it can be done!
Anyhow, hope you'll like my ideas on how to solve this issue!