Take the following diagram of 4 1.5V batteries connected in series to creat and net voltage of 6V (the numbers are of no significance here). If we were to short circuit the system by connecting battery 1 to battery 4 (or run the current through a load), wouldn't there be electrons traveling from the positive terminal of battery 1 into the negative terminal of battery 4 and accumulating there? Wouldn't this then create a net positive charge in battery 1 and a net negative charge in battery 4 until the current is inversed? This would matter in a scenario where you allowed such a charge buildup to occur and then seperated the batteries leading to the permanent seperation of those charges, no? The way I see it, the electrons do not have a way of returning to the negative terminal of battery 1. This leads to my second questiong which is: why is there a net potential difference of 6V if the only 2 electrodes that are interacting are the positive of battery 1 and the negative of battery 4? Essentially I don't understand the interactions of batteries 2 and 3 and their effect on the net voltage. If someone could explain the path of an electron in this system I would be very appreciative. Thanks in advance!