I’ve just made a new addition to my self-made power distribution system- a small voltmeter (the display with the numbers on the left, by the recorder). This allows me to see exactly how much battery power I have left They’re available from a number of sellers in China on ebay
I just soldered the red and green wires (+ power and voltage reading point) to the positive pin and black to 0V) on my power distribution box and it all works
Here’s the distribution box and battery:
It’s essentially a load of locking DC connectors wired in parallel