Shuts Down Frequently

I have a samsung galaxy exhibit 2 4g phone. It was charging fine a week ago and one day and all of a sudden it shut down and turned back on and shut down and back one. I thought it was battery and ordered a new battery. I barely got my battery today after waiting for a week and i put it in and it turned on & why i was unlocking my phone it shut down and turned back down and then i was back to where i was with my problem. I dont want to loose all my data & i cant restart my phone either ways because if i try it has already shut down.