The Boostcase Hybrid is a two-piece cover and battery case for the iPhone 4 and iPhone 4S that promises to give you extra power when you need it, but still be a slim iPhone case when you don't.

Available from Firebox in the UK for £59.99, the case comes in a variety of colours from pink to cyan.

The idea is that you snap the protective case to your phone when you are using it day to day. When it comes to needing extra power - a lot more extra power - you can attach an additional battery pack on to the back of the phone to provide another full day's charge: handy if you've gone camping for the weekend.

For those who like tech specs, the Boostcase Hybrid comes with a 1900mAh of recharging power - a lot compared to the iPhone's 1420mAh internal battery. 

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The battery case clips on to the phone case you've already attached and can be independently charged or if needed turned off so you can wait for the perfect moment for the extra boost of power. You can also charge the iPhone while it's attached via a micro USB connector - included in the box.

While the Boostcase Hybrid isn't that thick in itself, it will add extra depth and girth to your iPhone 4 or iPhone 4S, making it anything but pretty or small. The company has done its best, but it's still bulky. We wouldn't recommend you use this all the time - certainly not if you want to keep up that street cred you've worked so hard to earn.

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The fact that it slips on and off does add to the appeal though, especially if you've got docking stations or want to charge your iPhone using the standard docking connector.

If you find yourself in need of extra power regularly then this is one to consider. However, with the iPhone 4S quick charging capabilities, if you can plug in your phone - even for an hour - you can probably live without the extra bulk.

Thanks to for the loan of the Boostcase Hybrid.