Does the Edge 520 support an external power pack for charging mid-ride? 15hrs in optimal conditions is a little short for a 200 mile ride with navigation.
I did an 300 km ride with Edge 810 , no course loaded but with map activated and always display
also I am planning an ride for ~400 km , and I also need external power , the only drawback when cable is disconnected on 810, there is an message for shutdown