Don't expect to much out of the solar panel.
As long as you can position it in direct sunlight it will charge stuff.
But once it's in a bit of shade/overcast then forget it.
My 20 Watt panel will only just charge a couple of AA in light overcast.
A better bet if your not going the whole hub dynamo plus solar panel setup, which is the only way it will work in the UK because it can rain for a week, is a couple of big cache batteries and a mains charger.
Then pay a pound or so to get a battery charged up in the campsite office/house once it's flat while you can still use the other.
Downside is you'll have to wait for the office to open in the morning.
If you stop in hotels then power is not a problem.
One reason I stopped in a hotel every 4-5 days while touring in eastern europe was that was how long my cache battery lasted on that tour.
But if you camp then it can be so don't expect to be online every night.
As noted above, my satnav runs off a couple of AA and I carry a set of Duracells just in case I run all my recargables flat.
A Kindle uses less power than an Tablet so I preload all my documents/route plans (names of towns/villages, post codes for campsite, etc, etc) on to mine before I set out.
Luck ..........
