We have an ongoing list of top tough iPhone 4 and 4S cases, but a lot of folks have requested a roundup of top battery cases for extending your iPhone's battery life, so here it is.
A few notes: While you should be able to go a day without recharging your iPhone 4 or 4S, some people use their phones more than others--or use battery-intensive applications such as video--and need more juice than what's offered with the iPhone's internal battery. Most, but not all, of the cases in this roundup are designed to double the battery life of your iPhone.
Mophie makes one of the more popular battery cases for the iPhone 4 and 4S.
Many of the cases have batteries that are truly integrated into the cases while some have removable batteries that allow you to swap in additional batteries. And a few cases have detachable batteries that clip onto the back of the case.
Most of the cases try not to add too much bulk to your phone (who wants that?), but it's impossible to get around the fact that adding a second battery to your phone is going to add weight to it.
For those who can't deal with the idea of a bulked-up phone, another option is to buy an external battery charge... [Read more]