[Help] Laptop's Low Battery Warning

It started doing that a week ago. When the battery is running out of power the Low Battery Warning doesn't appear and now the Laptop suddenly Shuts Off. I've been observing it and i have come to a conclusion that the Power only last for like 25 Minutes and then Shuts Down. The power use to last longer before, but when the Low Battery Warning stopped showing up, the power doesn't last longer anymore like it use to. Does anyone knows what could be the cause of this problem?

Idk where I read it at but keeping your laptop always on a charger is bad for it. Idk if you do that or not, but it seems you might need to buy a new battery

Yeah, i made a scan to the battery and it said that it doesn't work anymore.
I have to buy one.

yea that allways happens to me it just randomly shuts off this laptop is basically fucked but i can manage with it XD