My project: Power a Beaglebone Black (BBB) entirely from solar energy. Obviously energy efficiency is crucial here. My setup so far: PV panel connected to a deep-cycle lead acid battery. Now I need to get from the battery's 12V to 5V (2A) for the BBB.
Most similar projects suggest the use of a UBEC (Universal Battery Elimination Circuit), like this one. However, I am not sure if this is the right thing for me. The efficiency curve of a typical UBEC drops pretty badly for low currents. I expect the BBB to spent most of the time idle, i.e. draw around 150 mA, which means that efficiency would be pretty low.
Is an UBEC the best solution or are there more efficient ways to supply 5V/2A(max) for my purpose? Since my soldering arts are rather limited, I would prefer a ready-made solution.