Greets, I have a large solar panel putting out on average 19 volts and about 1.3 amps shorted. Ultimatly I would like to make a nice portable power box for camping. It would be nice to have 2x12v car, 4 USB ports. I understand that they wouldn't all be usable at the same time. The need for the extra usb ports is for pesky cell phones like the iphone which needs a small circuit on the data pins. Also I would like to incorporate some batteries into the mix for some night use. I have a bunch of 6v SLA and a few 12v SLA batteries I was thinking about using. (unless thats a horrid idea) I recently used it on a camping trip to power my droid, a set of USB powered speakers, and another cellphone charger. I cheated however by using some 12v car chargers-to-usb for both the speakers and droid, and just a car charger for the other phone. I simply ran power from the solar panel to three female 12v cigarette jacks. This cant be the best way... right? I have thought about using 4 7805's and 2 7812's to achieve my desired results but I really am not sure if that is the most effecient use of the power provided from the solar panel or if those are even the proper regulators. Help I am pretty much a noob. Thanks in advance.