If you’re going to buy an external battery pack for your iPhone 4, you may as well make sure it’s one with plenty of power; so how about the MiLi Power Pack 4, as it has a massive 3000 mAh battery inside!  That’s more than double the capacity of the standard iPhone 4 cell.

The MiLi Power Pack 4 is more of a backpack than a case, as it doesn’t cover the whole of the phone, leaving the top poking out a centimeter or so, and only protecting three-quarters of the sides.  The piano black finish and silver highlights compliment the curvy design well, making it an attractive accessory to own.

The design is also intelligent, as the iPhone 4′s camera lens is exposed properly and there are two ports on the base of the Power Pack, ensuring the iPhone 4′s speakers aren’t blocked.  The iPhone 4 slides in easily, even with a screen protector fitted, and the 30-pin connector lines-up perfectly.  We did find the screen protector made removal of the phone a bit of a struggle though, so keep this in mind if you have both a front and rear shield fitted.

The Power Pack is activated with a button on its side, which is next to a series of blue LEDs indicating how much charge the battery pack contains.  Once inside, the phone is held tightly in place and certainly wasn’t in danger of falling out or being accidentally disconnected.  The Power Pack 4 is charged via a USB cable, which can also send power through to your iPhone 4 so you never have to remove the pack if you don’t want too.

But seeing as the MiLi Power Pack 4 adds 100 grams to the weight of the iPhone 4, we’re not sure how many will chose to keep it fitted all the time.  However, MiLi seem to have thought of this and provided the Power Pack 4 with a kickstand – for vertical or horizontal use – turning it into a desktop charging dock.  Ours was called into action when briefly away from home, and instead of bringing the charger and cable, the MiLi stood in for both.

It performed brilliantly, recharging the iPhone 4 from the 20% capacity warning to 100% twice, and it still had a little in reserve!  It was so convenient and so easy to carry around, it’ll be perfect for a future long-haul flight, as a couple of hours music, Infinity Blade and a video will quickly kill the standard battery; but with the MiLi to hand I’ll still have power when I land.

The MiLi Power Pack 4 is available from Powerskin for £59.99, which is very reasonable considering the 3000 mAh capacity, stylish looks and excellent build quality.  We’re happy to recommend it!