In a circuit schema, why the voltage at the battery anode is conventionally 0V while the voltage at cathode is usually the voltage of the battery?
Conventional current is &quot;upside down&quot; with regard to electrons, due to some arbitrary choices of labelling made centuries ago. That's why I normally suggest ignoring them and focusing on conventional current and voltage analysis.
Electrons are negatively charged. Each electron has a charge of minus 1.602176634×10−19 coulombs.
You could label the &quot;negative terminal&quot; -1.5V and the &quot;positive terminal&quot; 0V. Then your negatively charged electrons flow away from the negative side of the field (because similar charges repel) towards the positive side of the field.
(Electrons themselves do not really &quot;carry&quot; energy, the energy is embodied in the field, and the ability of the field to do work on electrons is the energy.)