ELECT. LEAVES ONE BATTERY PLATE, THEN RETURNS TO THE OTHER?

Not quite. The actual path of electric current is THROUGH the battery. Some books imply (or even state outright) that, whenever a battery is connected in a complete circuit, the charges flow only in the wires, and that no charges flow in the chemicals between the battery plates. This is wrong. These books often contain a diagram of a battery, wires, and a light bulb. The diagram shows the current in the wires, but shows no current going THROUGH the battery. This is wrong. In any simple electric circuit, the path of the electric current is a complete circle. It goes through all parts of the circuit including the battery, and including the battery’s liquid electrolyte. If there’s one Ampere in the wires connected to the battery, then there’s also a 1-Amp flow of charge in the electrolyte between the battery’s plates. Where does this charge come from? Go down to this section. A battery does not supply charges, it merely pumps them. Whenever electric charge flows into one terminal of a battery, an equal amount of charge must flow THROUGH the battery and back out through the other terminal. In a simple battery/bulb circuit, the charges flow around and around the circuit, going through both the battery and the bulb. The battery is a charge pump.