Is there an iPhone 4/4s case where you could snap on and attach an external battery?

IIm looking for an iPhone 4/4s case where you could simply snap on the battery when you need it, and when the phone is charged up, you take it off and put it away so the phone isn't bulky all the time. Or at least a power bank that hangs on the back of the phone and charges. IIm looking for something at least 1900mAh and under $25.

What if more power at less price?

3200 mAh @ $9.99

Here you go: http://www.amazon.com/...005X1Y7I2/

  • Would It Be Weird For A Guy To Have A White iPhone 5 With A Red Snap Case? I'm An Athletic Guy And Wondering If It Would Look Gay Or Weird For Me To Have A White iPhone 5 With A Dull-Redish Snap Case.
  • Will A Snap On Case Scratch My iPhone 4? Will Snap On Cases Scratch My iPhone 4? Ok so, my cousin gave me a snap on case for my birthday. And its cute and all, but 1 problem! Will it scratch my phone? I mean usually I don't put on those kind of cases because they don't protect my phone. I have 9 other cases but there silicone and they are protective. But I feel bad not putting on the case that my cousin gave me!
  • Sound coming from my external iPhone battery? This may seem like an awkward question, but since when did batteries make a whirring sound? It's not like they have movable parts inside like a hard drive. I'll post the link to the exact external battery later.
  • Snap chat? And iPhones? How much can you see? IPhone 5 has a bigger screen that iPhone 4. If I take a photo on a iPhone 4 and send it to someone with an iPhone 5. Will they be able to see more of the picture than I did when I sent it? Or do the boarders stay the same no matter how you view it?