Nintendo DS Lite Won't Charge When Plugged Up

As I was cleaning out the house, I came across this old Nintendo DS Lite, but I had no charger. I asked my friend to get his charger, and when I plugged it in, it’s light came on but charged slow. It took about 1 whole day to get it charged. It lasted for a few months then died.

I tried charging it again today, and the light wouldn’t come on. I left it for about a week or two and it wouldn’t come on. My friend said they think the battery might have “burned out” or “exploded, but not to the point where it popped the whole DS” or I might have “burned out the internal systems.”

Now, I’m not a tech genius so IDK what they meant, but if anyone could help I would appreciate it :)