I bought a 3rd party battery for my MBP. I put it in and after cycling the battery i noticed that the full charge capacity was only 3990mAh (supposed to be 5500mAh). I returned the battery today and got and an upgraded replacement. this shows the full charge capacity at 4995mAh (supposed to be 5600mAh). is this normal. Do I just need to give it some time or is it something with the batteries.