Razer Quartz Battery and OS Issues

I got a used Razer Quartz base model not too long ago, it thinks there is no power in the battery and it says it is 100%. When I unplug it, the screen goes black right away. The person I bought it from said she replaced the battery 6 months ago and has not used it in a while. HELP. And also when I tried to reset recovery it went back to windows 10 instead of 11 when I first turned this laptop on. It was on 11 before, what is happening?? This is so frustrating! Anyone can help with this? * I also realize now that it isn't even detecting a battery in there... what D: