Step 1: The Meter.
This meter I got off Amazon.com and it tells the capacity and voltage of the target battery bank. It has only one white pushbutton switch behind it from configuration. A long press is 3 seconds. To configure you have to;
Long press to get the first menu 1U. This changes the voltage offset of the reading by long pressing to go down in reading. To go up just release the button and long press again.
After the first long press, short press once to get the second menu. Long pressing this causes it to cycle through 4 values which are the nominal voltage of a cell chemistry. Since I'm on lifepo4 I used 3.2v.
After the first long press, short press twice to get the third menu. This allows selection of the number of series cells by a long press.
After the first long press, short press thrice to get the final menu. Long pressing allows cycling through voltage, percentage or both being displayed.
If any value is changed just leave it be for 3 seconds and the screen will flash to show it saving.