Problem is different people want different things. I for one want at least all day battery while using only about 60% of the capacity so realistically two full days battery from a single charge. I then want to be able to set a max charge limit of 80% beyond which the phone won't charge and have the phone die at 20%. Ideally, I also want the phone to be able to work off the wall meaning if the phone is plugged in to the wall, it should use power from the wall and not constantly charge and discharge the battery.