2 of 3 people found the following review helpful
Brilliant Battery Extender!,
This review is from: mophie juice pack air for iPhone 4s/4 (1,500mAh) - Black (Wireless Phone Accessory)
Customer review from the Amazon Vine Programme (What's this?)
This may not look the nicest, nor may it give the most protection, but if you're unsure if the battery on the iPhone 4 is going to be sufficient for your needs, this is definitely a well-worth investment.
Currently priced at over £60, this product originally retailed for under half that price, and I'd recommend shopping around as at £30, it's a snip. The phone looks slightly bulkier, but you can charge up to around 70-80% battery power, perfect for an emergency, and it's also very, very fast. It fits nicely onto the iPhone, and you can tell it when you want to re-boost your battery.
Overall, a very, very useful product!