Hi, I know how to replace a battery on an iPhone just for the record, so please don't post on how to do it. My battery lasts about 4 hours used+ over 36 hours standby from 100% to 20%. I wondering if that's a good amount. Also I'm wondering if there is a way to add a battery pack that is better than the one that comes stock. I know that many android phones can have bigger batteries installed into them, and I'm wondering if anyone knows of a battery for iPhone that will make it last longer than the stock batteries. I've never heard anyone talk on forums anywhere about this, and I searched and only found external ones, and also the original/stock type ones... Anyone know of anything?