I just had a few confusions with battery voltage and overall how it worked. I tried searching online but the answers were so general they didn't explain "why". To start when we are using up a battery, essentially the chemical reaction in the electrolyte pushes electrons to higher potential (electrons to the negative terminal). Does this reaction continues throughout time or are the electrons already at the highest potential prior to using for a new battery? Moreover, when the electrons flow when wires are connected, does the voltage in the battery decrease to 0 as the electrons flow back to the positive end? In a sense shouldn't the voltage be 0 as the electrons are all pushed back to lower potential?
1 Answers
Does this reaction continues throughout time or are the electrons already at the highest potential prior to using for a new battery?
The reaction continues over time. Like many chemical reactions the speed and even the direction of the reaction depends on the amount of products and reactants available.
In the case of an unattached battery the products accumulate rapidly on the terminals. This produces a certain voltage which is characteristic of the reaction. At this voltage the reaction stops.
In the case of a battery attached to a circuit the circuit removes some of the reaction products from the terminal. This drops the voltage slightly and allows the reaction to continue.
The flow of electrically charged products is an electrical current. So the current identifies how fast the reaction is proceeding. A well designed battery can change the current quite substantially with a very small change in the voltage. So it approximately functions as a voltage source.
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