@nigelhealy Ok, so you peeked my interest. Here are a couple of questions for you......
1) Can you use your phone while "charging" the solar panel?
2) How long does a charge hold?
3) Is it safe to leave on your dashboard for hours?
4) Compared to say a Powercore power bank, what's the charging time (how fast can it charge your phone)?
5) How reliable are they?
I've only had one experience with a solar charge bank. Bought one on my way out of Cedar City, Utah at a pawn shop and not even a day later, it was totally dead. Unfortunately, I couldn't go exchange or get a refund since we were on a road trip. That experience left a bad taste in my mouth. And to make matters worst, the battery started expanding. I ended up chucking it. Wasted $40.
I would love to get one to use on road trips. Something I can leave in the car until needed.