Experiment 16 - Practical Comments II (Series Circuit)
Using several batteries connected in series circuit
results in some practical comments when
keeping your knowledge of the internal resistance
and the dependence of the state of charge in mind...
In a series circuit of batteries you should never mix
fresh batteries with used batteries.
From the experiment 8,
you know that the internal resistances are added
in a series circuit.
A depleted battery in series circuit dominates
the internal resistance of the circuit.
Use batteries of same capacity
This comment is closely connected with the last comment.
In a series circuit you should only choose batteries of the same capacity .
In a series circuit the same current flows through each battery.
Therefore, the low capacity battery is exhausted more quickly.
The internal resistance of a depleted low capacity battery
dominates the series circuit.