This company has made Solar panels(both portable and for whole homes) with battery storage built in. Could be a game changer, but I've heard that prematurely before.
SolPad Mobile | Solpad
Update: "Ikea" seems to offer the same solar/battery storage system for home.
IKEA rivals tesla with home solar panels and battery storage packs
Interesting idea, but I would think it would be hard on those built in batteries to bake in the sun, all day, every day.
Yes, that needs to be answered. Car batteries, given that they are blocked from direct sunlight, survive some high temperatures. If these batteries do work ok, I wonder if the storage will be sufficient to power whatever device all night and during overcast days. In addition to the batteries, the built in convertor seems ideal for the DIYs. We shall see.