phy1020.DVI

a total potential of 12 V. Sometimes a single electrochemical system is called acell, with the word “battery”
being reserved for several cells connected in series.
It’s also possible to connect several batteries inparallel, so that allCterminals are connected together
and allterminals are connected together. This arrangement will have the same potential as a single battery,
but will be able to delivery more electric current. This is not usually done, since one could simply replace the
multiple batteries with a single larger-sized battery instead.
In a real battery, the potential delivered by the battery is not constant, but varies with the amount of current
delivered by the battery. This is due to the battery’sinternal resistance, and is discussed further in Section
20.5.
A good way to think of a battery is as a kind of electron “pump”: it pumps current around and electrical
circuit, much like a water pump would pump water.