MFI Apple iPhone 4 / 4s Hard Cover Power Pack for iPhone 4 & 4S in black with 1800mAh battery

Initially, I was very excited. The cover looks neat, does not bear heavily on my iPhone and I can be refueled at a pinch again.
Unfortunately, making the incomplete fit, as already described By Some reviewers, by higher clearances negative impact. Here the daily dirt accumulated in the gaps and ultimately leads to scratches on the device.
The final cap (above) sits quite loose. The risk this cap is loose with occasional dress and undress the case quite large.
After a short while the initially high appearance Case suffering by solving the matte surface by abrasion.
Is the Case of the battery is fully charged, the charge capacity should be sufficient to the iPhone once fully loaded. I could only find a complete charge of the iPhone (by case), if the iPhone had a quarter of its battery capacity.
Last criterion and therefore the exclusion criterion was the heat that was in charge of the case.
I recommend: before charging the Case only get the iPhone. But then will certainly not increase the durability.