Chosen Solution

Please help me with my PS vita it does not turn on when I unplug it from the charger even though it’s fully charge. when I plug the charger in it turns on . I tried everything, I push the three buttons, I restarted and formatted it buts still not turning on. It suddenly furn off when I’m about to use it, I haven’t use it for about 2 years and when I stared using it again it lasted for about a day then this problem came. Pls help me fix my vita 8

It may be that the battery is not taking charge thus when unplugged dies instantly.