Batteries

"battery" is a set of voltaic cells designed to provide
greater voltage and/or current than is possible with one cell alone.

The symbol for a cell is very simple, consisting of one long line and one short line, parallel to
each other

the voltage produced by any particular kind of cell is determined strictly
by the chemistry of that cell type. The size of the cell is irrelevant to its voltage. To obtain greater
voltage than the output of a single cell, multiple cells must be connected in series. The total voltage
of a battery is the sum of all cell voltages.

The cells in an automotive battery are contained within the same hard rubber housing, connected
together with thick, lead bars instead of wires. The electrodes and electrolyte solutions for each cell
are contained in separate, partitioned sections of the battery case. In large batteries, the electrodes
commonly take the shape of thin metal grids or plates, and are often referred to as plates instead of
electrodes.

For the sake of convenience, battery symbols are usually limited to four lines, alternating
long/short, although the real battery it represents may have many more cells than that. On occasion,
however, you might come across a symbol for a battery with unusually high voltage, intentionally
drawn with extra lines.

The ideal battery, in a short circuit with 0 ­ resistance, would be able to supply an infinite
amount of current. The real battery, on the other hand, can only supply 50 amps (10 volts / 0.2 ­)
to a short circuit of 0 ­ resistance, due to its internal resistance. The chemical reaction inside the
cell may still be providing exactly 10 volts, but voltage is dropped across that internal resistance
as electrons °ow through the battery, which reduces the amount of voltage available at the battery
terminals to the load.