Can you damage an iPhone by charging it using a (homemade) solar panel?
The LiPo charger used is a LiPro Rider Pro, that charges the LiPo from the solar panel (or usb) using a LiPo charging regulator and also steps up the voltage from the battery to 5v for usb out, using a switching boost regulator. See Seeed's wiki page for the charger for more details.