I lost my whole Lvl 60+ Team: The frustrations of being a pokémon master

[Hoeloe]

I've had the same save file on my Pokemon Yellow version since I was about 7 (that's 12 and a half years). The battery is about to (may have already) run out, so I'll be losing my save data soon. In some ways it would be kind of nice to start again, but I put a lot of effort into that game (and it was the first save file I ever got a level 100 on).