After reading tj1772's quote in another thread:
So the question is -- how many amps are needed to run the DX with various apps running. In the car on road trips, I can see myself using Navigator, playing music and using the hotspot (for the kid's iPod Touches). This last weekend I took a 2 hour road trip and only used the Navigator. I started with a fully charged battery and at the end of 2 hours I was at 60%! I was using one of those Scosche Dual USB car chargers. It is supposed to put out 1A and I only had the DX plugged into it. So is 1A not enough?