Tablet battery draining

[Sassy12]

I have a lenova yoga 2 tablet android software great tablet but the problem im having is i can charge it up to 100% which is great and ise it no problem but of i turn it completely off not sleep it will refuse to turn on till i plug charger in and thats when it will say 0% battery also if im using the tablet and it gets down to 25% battery it will turn off by itself and refuse to turn back on even if i plug charger into it and it can struggle to turn back on for ages. I keep it clean of junk i also have spyware on it i only use it for films only no games no social media nothing else but films please somebody help its also recently been formated thinking this might help the issue which it hasnt

 

[webworkings]

Sounds like you may just need a new battery.