Does it move again to the negative terminal or stays at the positive terminal until the electrons all come .so the voltage will.be zero and current flow .I want simple clear explanation because i am confused .when I see a circuit that has two batteries one charging the other so I don't know how to think about it .i guess that electrons come from the negative terminal of the battery of higher emf to the negative terminal of the battery being charged and stay there but if this happen how the current moves to the positive terminal of the battery of higher emf.
Generally charge (negative) moves from anode to cathode and the chemical reaction in the battery is mediated by a salt bridge (may be different for various battery types). The salt bridge keeps the charge of the total system from separating completely and, in effect, slows down the electro-chemical reaction so that the battery isn't depleted almost immediately. This means that once charge moves through the loop there exists an unbalanced charge distribution in the entire system. The salt bridge supplies ions to the electrolytic solution to maintain neutrality but does not move individual electrons. Without the salt bridge there would be no way for charge to continue to flow and supply power to any connected load. This means that although some electrons may be transported through the salt bridge to move through the loop again the majority complete the loop once and either remain at the cathode, or bind to an atom to become a anion and are absorbed by the salt bridge.