Battery Block:

    9 volt batteries are the worst batteries ever. This 9 volt power block is a 3.4 volt lithium polymer 1.5 AH. This is feed through a USB 5V battery management circuit that allows it to be charged from a USB port. See small slot at end of block. Two holes on top show charge status LEDs. 3.4 volts connects to boost converter for 9 volt output. Not bad for most circuits. Slight bit of switcher ripple on output that probably impacts AM radio circuits. Maybe not, but I intend to do surgery on this block and add some additional output filtering.