Crystal Issues

[Pokémon Spectrum]

If this sort of thread already exists, I apologize, but I don't feel like browsing through the entire forum looking for it.

I just restarted my copy of Crystal, got to Violet City, saved, and shut the game off for a bit to figure out why YouTube apparently decided to skip three videos on the playlist I was watching. When I turned the game back on, the in-game clock was 15 minutes slow, which is approximately the amount of time between shutting it off and turning it back on. Is this a sign that my game's battery is dead? Or is this some other issue? I ask because my brother has figured out how to change the battery in GBC cartridges, but I don't want to waste money on a new battery only to find out that the error was from some other issue.

Edit Just to be exact, the clock still works, but only when I'm playing. Whenever I turn it off and go back to it, it's still at the exact time of day it was at when I saved and turned it off.

 

[Lucifer Morningstar]

I myself had this problem a few years ago with my Crystal cartridge though my clock was way slower, I'd started a new file during one evening and it was still night in the game the next day.
When I asked about it here I was told it was a warning sign of the save battery dying. Shitty timing too, I'd caught a shiny Gastly and had no way to trade it out to another game, still don't though the file is probably gone by now despite that I'd stopped playing it when I was told this.

 

[GuriBuru]

I hope I don't encounter this, as I just bought a copy of Crystal the other day...it's pretty much impossible to tell how close a battery could be to dying when you buy a used copy, unless they implicitly say they have replaced the battery.

 

[Pokémon Spectrum]

Well, I guess it doesn't matter either way. We got replacement batteries, but my brother couldn't get through the solder they used to keep the battery in place. He thinks that that's how they fixed the "dead battery=unable to save" problem that Gold and Silver had. If either of you figure out a way to remove the battery without destroying the circuitry, please let me know.