Rechargeable cartridges

[Oldewindmill]

Not really a spoiler, just casual chit-chat.
Hey guys, it's me, the annoying n00b who thought he could do a GameCube (or indeed, anything at all) with money he made over the summer, ended up frying three GameCubes and getting all his parts thrown away by his parents, made a mistake only ubër-n00bs make and asked for a ban, and did not go on modretro again for months out of sheer shame, only to mope in his own melodrama full-time (Half of that story's true. half of it's not. you decide). Now that we're done with re-introductions, I have a simple question:
Please explain the concept of cartridge batteries. Do they recharge as the cartridge is used?
If not, would it be possible to mod a console and your cartridges to do so? Perhaps in the space between the pcb and the cartridge's plastic shell, in that little empty area at the bottom, you could mount a port which connects to another one you put in the cartridge slot?
Of course to do this, you would need to wire the console's port to get power directly from the wall outlet, which could be messy, and you would need to open up the cartridge itself and replace the battery with a small rechargeable one, which is almost certainly bigger then the one included... so you would need to do a cart pcb reduction (has anyone ever done that before?) and/or make the cart enclosure bigger at the top.
As a result, however, your saves would be everlasting, assuming you played regularly.
Thet's hope this lame idea of mine is a tad more feasible them my last idea. (warning: Link contains very high amounts of excessive idiocy)

 

[CamaroCam]

I too had some disappointment when I discovered that cartridges use batteries, but I did a TON of studying to offer some comfort to the subject. Because who wants their perfect file on [insert favorite classic game here] to be gone forever? No one!
-Cartridge batteries typically last longer, if you keep the cartridge in good shape, and moderately cool temperature. Not too cold though, you could damage it.
-Most NES games don't actually use batteries because, they either use pass words, or they go arcade style. Only games with high scores use them, and then a few others that actually have progress (i.e. Zelda, and Kirby's Adventure)
-Almost all SNES games use them, there's no stopping that. but they usually have about 15 to 30ish years in 'em. Depending on how much you take care of them.
-Original Gameboy, and Color are the same deal as SNES, just with a smaller battery.
-Only a dozen or so 64 games use batteries(Unfortunately that includes Ocarina of Time, Super Smash Bros. and F-Zero X, among others.) But the rest use either Flash Ram, or EEPROM, both of which are non-volatile, which means they require no battery to keep your savegames, and thus last as long as the cartridge does(once again, your call, keep them in good shape.)
-Very similar deal with GBA. For the first few years or so, they used batteries, but then they switched to flash, which you can compare Ruby and Sapphire versions with FireRed and LeafGreen versions(the former use battery, the latter use flash) because they have translucent cartridge encasements.
-and finally they gave it up when the DS came along(part of that is probably due to the fact that the cards are too small to contain a battery) so no worries there.
-I don't know about the others, but I assume it's the same deal for Genesis, 32x, Maser System, Game Gear, etc..
-You can replace these batteries with fresh ones, given you have the right tools, and skills, but you won't need to for years. Plus the batteries are SUPER cheap.

All things considered, you got nothin to worry about. For quite a few years.

 

[Mario]

You're overthinking this. The cartridges already get +5v (NES, SNES, maybe Genesis) or 12v (N64). You can tap into that to charge the battery.

The real problem is, you would need to modify every cartridge with a rechargeable battery and some circuitry to let it be charged without disrupting the save data.