So I let me iPad Air run down until it was below 10% battery. I know it's good to do a full cycle charge every now and again. However, I plugged it in so it could charge and it's taking forever. Whereas my iPhone5 was below 5% and it's charging much faster. My iPad Air is using a wall charger and my iPhone is charging via USB plugged into my MacBook. Is there a better way/faster way to charge between wall charger and USB into MacBook charge?