I recently bought a set of all five Gen 3 games (Fire red, Leaf green, Sapphire, Ruby, and Emerald) off eBay. They ran absolutely fine, until about five minutes ago. I had 42 hours on the thing and my battery was low, and I went to save and the Gameboy shut off. I pulled out Emerald and plugged the GBA into the charger, went to find my DS and plugged the game into there. The game file had completely disappeared. No notice of corruption, save file deleted, or anything. I went over to my Gameboy and plugged Emerald back in there, and yep; the game's still completely gone without a trace.
I know that theres a possibility that these games are "pirated" and I looked into this; the game seems real until apparently its supposed to have a foil / metalic looking label (the ones on pirated are supposed to be more glossy?) would this have anything to do with the save file being buggy? Why was there no notice of deletion? Can I prevent this?
P.S --Much rage--
Yes you CAN prevent this. This may already have been cleared for you, if it does, sorry for a "re-post" :P
Well, the Pokemon games have an internal battery to store save-games and time-based events in the games (Gen.1 not included because these games did not have time-based events yet such as Day and Night like you would find in Gen.2 and growing Berries in Gen.3) and only in the Gen.3 games you could still save, but not take part in time-based events.
These batteries will last like 10-15 years until they run dry and therefore, it isn't possible to save your game. If you already have a saved file, this would either be erased or you CAN still play them but they just won't save or it isn't possible to do time-based events anymore.
About the warning, sometimes when you start up your file, it says something like: "The internal battery has run dry. ... Time based events won't occur" or something like that. Your game doesn't have to be pirated, just like said earlier, you should compare your games with legit ones.
I had the same thing with my R/S/E games, R/B/Y and LeafGreen but I was still lucky to have my saved files. Simple thing, especially when you buy second hand games from the internet, there is a high possibility the internal batteries have run dry.
So, the way to fix this, is to take your games to a Gameshop (preferable those shops that still sell retro games and consoles), and let them fix the internal battery for you. Please note that when you do have saved files on them, those will be ERASED when they change the internal battery. These things aren't that expensive and you can play and enjoy the full game again :)
However, there are people saying it is easy to fix these games yourself (Youtube) but that's utter nonsense if you'd ask me. I am a retro game collector, and I know for a fact the batteries sold for these games on the internet are 99% of the time not even compatible with the actual games, and you have a high chance to ruin your games if you would try to replace the batteries yourself. So I would recommend you should fix those games by someone working in that kind of a gamestore and believe me, you will be happy with the results (I know I was) :3
Have fun playing the good old Pokemon games!;)
Edit: the legit games do indeed have some kind of Metallic/glittery gloss as a label. You can recognize pirated games by several characteristics: for one, often the labels look really blurry and they look like they are "squeezed" together (the picture, letters on the label I mean) to fit AND they dont have a Metallic/glittery gloss. Second, the cartridge isn't transparent (like the R/S/E and FR/LG games) OR the R/B/Y cartridges are gray like most of the Gameboy Classic cartridges eventhough they should have the corresponding colour. Third, a MAJOR flaw that is easy to recognize is that sometimes, (especially on the old Gameboy Classic cartridges like R/B/Y) you find the logo "Game" instead of the (legit) "Gameboy" logo.
If you find anything that overlaps the things I mentioned above, then your games might be pirated and yes, your DS kinda knows when a game is pirated so it wipes out your saved data...