never minf=d i reset it and it works now thank you for all your help

I dropped the phone and it stopped working... I bought a new phone and just placed the iphone away in my desk. I was cleaning out my desk the other day and decided to try to turn it on. To my surprised it turned on, all my info was still on it & all the features were working as well. I restored the phone back to the factory settings and left to charge. After coming back a couple of hours later I could not get it to turn on again! i think its the battery so please help your supper if you do