Here are some pictures of how I am distributing the battery voltage. I gutted a old router for the case and mounted a Voltage/Current meter, current shunt and a terminal block.
Here is a view of the inside:
Here is the back view:
Here is the front view:
Here is how I power my Raspberry Pi's:
I took an adjustable buck converter and set it for 5.1 Volts and connected the output to the power wires of a 4 port USB plug I salvaged from an old PC I recycled some time ago.