I've been trying to visualise what is going on inside the batteries when you connect, lets say two 1,5V batteries, and why the voltage is added to 3V.
Several good explanations have tried to explain it in different ways, batteries as pumps etc. But I have never actually got a good picture of what the electrons are doing that creates the additive voltage effect (do you like my jargon). Until now. Introducing: the super explanatory theory of electron behaviour in serial connected batteries. Well maybe not, but I would like some feed back to see if I am on the right tract to understanding this mystical phenomenon. Here goes:
Lets this battery for example:
anode: Zn(s) + 2OH−(aq) -> ZnO(s) + H2O(l) + 2e−
cathode: 2MnO2(s) + H2O(l) + 2e− -> Mn2O3(s) + 2OH−(aq)
When the battery is unconnected, some of the redox reaction above will take place, creating free electrons in the anode and removing electrons from the cathode, until the energy needed to dislodge electrons from the cathode is to great, and the reaction stops. This creates the voltage (electric potential) for the battery. More electrons in the anode the more they want to go to the cathode, meaning higher Voltage .
When you complete a circuit each electron moved from the anode to the cathode facilitates a new chemical reaction replacing the electron at the anode, keeping the reaction going with even Voltage until the materials are spent.
If you connect two batteries in series without completing the circuit the electrons in the anode of battery 1 rushes to the cathode of battery 2, which in turn pushes the chemical reaction in battery 2. Thus you have twice as many electron is the anode of battery 2 and the original amount of electrons in the cathode of battery 1. Hey presto double voltage.
Am I at all correct in my impression of what is going on?