Polly is probably right about the battery. But another cause of Error 1611 is your computer Hosts file blocking Apple from signing your firmware. This is a good thing if you are Jailbreaking and Unlocking your iPhone. Anyway you can check if this is the problem very easy. Search on your computer for Hosts. Open the Hosts file and see if any lines have gs.apple.com If so, this is the problem most likely, and not the battery hopefully.