Q: iCloud backup estimated time 8  hours then fails, how can I back up??

I Have an iphone 5, version 7.1.1. 16GB, I tried to update iCloud but it wouldn't let me because of lack of storage space. I deleted my iPad to free up storage.

Now when I try and back up it estimates completion time to be 8+ hours. My phone is locked and on charge but when I check it after a couple of hours it states that the back up has failed.

I Have a new iPhone 5S but want to back up my 5 before I start using 5s, any help would be appreciated.

THANKS