Laptop shutting off suddenly

[lucindaa_rebelde--xo]

My laptop (Lenovo G50) keeps suddenly shutting off (i.e. black screen) when my battery reaches about 20%.
This happened last year intermittently, but I've since replaced my battery, and it's started up again. The hard drive isn't hot, there's nothing else that seems to be wrong with the laptop. Is this something to do with the battery being faulty, or perhaps something else internal?

What do you guys think?

 

[popatim]

In windows Power management, see what battery percentage it is set for to shutdown the laptop.

 

[lucindaa_rebelde--xo]

In windows Power management, see what battery percentage it is set for to shutdown the laptop.

Hello, I should have mentioned I'm using Windows 7. Under the advanced Power Options tab, though, everything is set to 10%, but shuts off (hibernates, rather) at 7%, which I think is all default.