We have two Anker battery packs, one 10,000 mAh and one 20,000 that we paid $19 and $45 for respectively. My wife and I have Samsung Galaxy s8s with 3,000 mAh batteries. We are going to get the kids something so they can play games while standing in line. We are hoping that the 20,000 is enough to keep all 4 of our devices charged.
My two biggest concerns with Fuel Rods are 1: Not many places to change them out besides Disney. I live in Wisconsin, the nearest place for me to exchange a FuelRod is the Minneapolis airport and there is no where within 100 miles of Chicago.
2: Capacity. They won't say how big the battery is, but everything I've read put's it at around 1,000 mAh. Or 1/3 of my cell phone battery. So I would need to swap out twice just to fully charge my phone.