Hello, Today I noticed an issue with my iPhone 5 screen, it felt lifted on the edges. I did a bit of research and found out that it may be the battery expanding. Being worried I opened up my iPhone to find that the plastic side edges of the screen assembly were splitting off from the screen assembly part itself. Okay minor issue, I can just get a new screen assembly. However, looking at the battery it felt like the plastic packet/casing of the battery was slightly detached from the battery itself. When I ran my fingers over the battery I could feel the gap between the battery and its casing. Could this be the gasses causing the casing to lift slightly from the battery? I did make out a very very minor bump towards the top of the battery. Is this okay or is the casing supposed to be fully sealed around the battery? This is a used Ebay iPhone 5, its exact age is unknown, will Apple replace the battery for free seeing as its a defect?