Bought new battery, having issues since

Hi there. 

So, I just recently bought a new battery for my XPS 13 9343 laptop, as the one old was at the end of it's life.

Since I installed it i'v been having some issues with the computer, mainly it randomly shutting down at different times. It doesn't even matter when, it will just shut down. It's done it to me a few times while i'v been using it, but mainly it happens when I close the top. I'll come back to find all my programs and everything shutdown, without me having turned it off. It wasn't doing this before, all just after I installed the new battery.

For context I bought this laptop back in 2015.

Can anyone help me with this issue?