Well, I totally disagree with the last comments. I needed extra power so I can keep myself entertained on flights or whilst travelling. I saw this on sale, admittedly at a sale price, and bought it as time was short.

A quick glance at the intructions and I was away. Phone slides into the case easily and is locked in via a small tab. I found this not to fasten very well until I bent it a little. This is a weakpoint of the case as I can imagine you can break the tab off if you are not too careful.

As to the operation of the battery, you can actually charge both this case and the Iphone at the same time. Using the, admittedly, short micro USB cable you press a button on the back of the case. This makes the Iphone beep, to recognise the charging process, and both battery's will receive charge. I found you had to also press this button for the phone to be recognised in Itunes.

The charge for both items was about 3 hours, ish. Yes the screen is unprotected but is made of toughened glass so, in it's own right, is strong. I have dropped my phone whilst in the case and neither received any damage.

As for the performance of the battery pack. I am really, really happy with it. I watched a film of over 2 hours and my power guages hardly moved. The Iphone has it's own guage on the phone and the battery pack has 3 blue led's to show it's power resources. 3 = 100%, 2 = 80%, 1 = don't know.

I have seen many packs advertised on ebay etc and was wary of buying from there as a lot of fakes are in circulation. I bought from Maplin because I would be happy that it was real and would perform well. For the price, I would recommend it.

Sure, it is not Mophie or Air but I would buy one again. Maybe Maplin might hopefully have them on sale again soon. If they do, go grab one, you won't be disappointed.

Can't fault it. Using iPhone with Viewranger App for navigation after nearly 12 hours phone was on 73% battery.

Hum not entirely happy with this product but price was right at the time. Pro's: Ideal if your not near a power supply to charge phone on a daily bases when travelling. Yes probably the smallest battery case I've seen. Dislikes: You cant charge both the iPhone4 and case battery at the same time, you can either charge case battery first and then charge the iPhone from case battery, this requires manual intervention to get full charge on both batt's, so not auto for over night operation. Would of liked to have seen better protection to the front of the phone as used for travelling. It's a hard case not rubber or ruggedised so not good for the phone or case if dropped. Difficult to take out from case so if you dock the phone at home in a base station then fiddly to remove. Uses micro usb to charge case unit plus the supplied cable is shorter than regular iPhone sync cable. Operation: When iPhone is low on battery you push the cases flush mounted on/off switch, has 3 small led's on case to show charging status to phone or actual charge left in case batt. When usb power supplied pushing the on/off switch either charges the battery or another push charges the phone battery. That's it!!