Credit: Rita El Khoury / Android AuthorityIf you’ve ever felt slightly cheated by even the best power banks, you’re not alone. At first glance, a 10,000mAh battery pack looks like it should recharge your 5,000mAh flagship phone twice without breaking a sweat. Yet somehow, the numbers never seem to work out quite that neatly. A charge and a half, or thereabouts, ends up being much more realistic.The good news is that your power bank isn’t lying to you. The bad news is that battery capacity is a little more complicated than the box’s marketing makes it seem. The milliamp-hour (mAh) figure you’re looking at doesn’t represent the amount of charge that will end up in your phone, and that’s where most of the confusion begins.