I am having trouble understanding how to assign polarities to voltage when it goes through components of a circuit and how those polarities determine the sign of the quantities I put in the KVL equation. Attached is a picture of a circuit. The points where polarity matters are labeled 1-14. I am trying to find the voltage of battery 1/2. I know how to assign polarities to batteries but are there any rules I should obey when assigning polarities to resistors? Also what happens to voltage when batteries are connected like battery 1/2 and battery 3/4 in the picture? Also when putting quantities in the kvl equation how can I determine which quantity is positive and which is negative? and lastly what role do polarities play when solving circuit problems?