I've only ever had to charge my gps from zero one time with that set up. Most of the time I keep my GPS off till I need it then I top off my phone and gps at night. I'm willing to bet I could get two full charges out of it. It's charged my iphone 7 plus twice and my gps once, both from zero on...
I tried the nomad solar charger but had minimal success, I just don't have time on my hunts to be tinkering with the (very) slow charging solar panels and I don't have the room in my pack for a gigantic panel. I picked up a dark energy charger, and swapped all my electronics to USB rechargeable...