It is easy to tell if it is charging from the PV, and it is easy to tell if it is providing a charge to the iPhone (Pad). It will be helpful in many situations our of the house.
I bought these for my two grown adult children who live in NorCal for Christmas presents. I won't know the quality until they use it after the first of the year. The shipping, communication & products we're in great shape & very timely.
My last trip to Europe, I went on a tour. I was the only one on the trip that didnt worry about running out of charge, thanks to this extra battery. The solar part is slow, but it works great as an extra battery. Need a larger solar panel for fast charging.