Originally Posted by Ken Maltby
Having even a number of small panels go to an adapter, designed to regulate the power from the much greater amp capacity of an automotive electrical system, is a simple and inexpensive measure to insure compatible power for your device.
Simple and inexpensive, yes. Unfortunately not very efficient. As can be seen from my tests, these adapters don't do a great job of converting the 12V down to 5V.
My test adapter, and another rather more expensive Motorola SYN0847 adapter
, were both only about 70% efficient. 30% of the power coming from the panel(s) will be wasted as heat in the adapter. The power output capabilitiy of the panel(s) has to be increased to compensate.