The Lamar register., 1923-01-17
HOW THE STORAGE
BATTERY OPERATES
Operator Must Guard Against an
Excessive Rate Of Charge
or Discharge.

charging process. However this Is
long and tedious process to get oxide
of lead on the positive plates by means
of numerous charging and discharging
cycles. The oxide, which is the active
material is manufactured chemically
and applied to the plates.
The body of manufactured plates is
cast from lead In such Il manner as
to leave the surface honeycOmbed In
this honeycombed surface of the
plates Is forced paste. formed by
mixing litharge-lead-oxide with sui
phuric acid After the plates are as
sembled with separatOrs between they
are placed In containers in an electro
lyte consisting OF 20 per cent so
luton of sulphuric acid. The lead
body of a storage battery plate simply
acts as Il holder or container for the
active material. The active materials
in lead storage battery are the lead
peroxide on the positive plate, the
sponge lead OF the negative plate and
the sulphuric acid electrolyte.
When a storage battery is dlscharg-
ing. that is, while a current Is being
drawn from II, u chemical action takes
place in the battery. The lead per
oxide Of the positive plate and the
sulphuric acid of the electrolyte react
to form lead sulphate and water. Acid
is more dense than water. so that
when fully charged the electrolyte has
"A density OF 1875 to 1900. which
means that the electrolyte Is 1.27o to
l.8 times as heavy as an equal volume
hat Il sch ~
and water Ia formed by the chemical
action. the electrolyte becomes less
dense Finally, when the density
drops TO 100 to l.150. the battery
reaches a point when charging is nee
ezsary. Thus the density Of the cleo
trolyte Is a measure of how much en-
srgy. or how fully charged the bat
terry is
The voltage Of a battery is also
an Indication of the degree OF charge.
fully charged battery should have
an open circuit voltage OF % volts
per cell.
The voltage per cell should not be
allowed TO drop below Is before re-
charging.
When Il storage battery is put on
charge. direct current is forced
through the battery. The chemical
reaction that takes place during the
charging process Is just the reverse
Of that which takes place during the
process Of discharging. That is to say.
the lead sulphate and water formed
during the discharge are converted
back into lead peroxide and sulphuric
uI,.t, 10
acid during the charging process
causes the density Of the electrolyte
TO Increase The density OF the cleo
frolyte of fully charged battery is
between l275 and 1900. while the
open circuit voltage per cell is about
-
or course, a storage battery is not
100 per cent efficient. which means
that the total anpere hours delivered
to the battery during the charging pc
riOd will always exceed the total am
prre hours drawn from tn" battery
during the discharge period. The
voltage per cell and the specific gray
ity Of the electrolyte are the criterion
OF the degrees Of charge In the battery.
However. due to the fuct that some of
Lht ltdu sulpIult II ubl Itduliy toh-
Nerted into lead peroxide and sui
phuric acid. It Is necessary at times
to give the battery an over
charge That IS. the charging cur
rent should be allowed TO flow after
the battery has reached the charged
condition, until after several hours of
constant charging there Is no in
crease in the voltage per cell or the
density of the electrolyte.
The value of the charging current
is determined by the manufacturers
and should not be exceeded. An ex-
oessively high charging current will
cause an increase In the rate Of de
terioratlon of the plates. Every time
battery is charged or discharged
certain amount of active material on
the plates crumbles and drops to the
bottom OF the cell.
Assuming the same operating CON
ditiOns, the life of a storage battery is
a certain number of charges and dis
charges An excessive rate Of charge
or discharge will cause the battery TO
heat, buckle the plates. and result in
an abnormal amount Of crumbling of
the active material In the extreme
case Of a short circuit, the plates of
the battery might be buckled to such