BuyDig is offering the uNu iPhone 5/5s MFi battery case for $45 with free shipping when you enter coupon code IPHONEJUICE at checkout. That’s $35 below retail and $10 better than Amazon’s current price tag. It is MFi Apple-certified and as such you will not have any nasty iOS7 warnings/threats about using a ‘non-compatible’ accessory. Not to mention you won’t risk damaging your device. The 2300mAh built-in battery will provide enough juice to tack on an extra 10 hours of talk time. All ports and button remain accessible when the case is installed. Only available in black. Over 225 Amazon reviewers rate it 4.5 stars.
Tanga has the iPhone 4/4s version for $30 with free shipping. Available in white, black, and silver.