To provide some context: I recently bought a second-hand New 3DS XL and everything seemed okay; except the battery, which ran out just 30 minutes after I first turned it on. I messaged the person that sold me the product and they said it's 'normal' because the console is many years old. Also, they said the capacity of the micro SD card made it run out faster (I think it's a 32gb card).
The thing is, the battery SHOULDN'T die only 30 minutes in (that's not normal lol). Also, the console says it is fully charged and suddenly it starts going down VERY fast.
So my question is, I've seen many people say that people often buy 3DS batteries online and just replace it. Would it solve my problem? Is it easy to change? I never really opened the console and it's kind of scary. Would you recommend trying?