The Bozeman courier. (Bozeman, Mont.) 1919-1954, 1923-01-31
RADIO
HOW THE STORAGE
BATTERY OPERATES
Operator Must Guard Against an
Excessive Rate of Charge
or Discharge.

ing through the nargng anu us
charging process. However, this is a
long and tedious process to get oxide
IF 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 a manner as
to leave the surface honeycombed. In
this hOneycombed surface Of the
plates Is forced a paste, formed by
mixing lithargelead-oxide with sui
phurfc acid. After the plates are as
sembled with separators between they
are placed In containers In an electro
lyte consisting of q 20 per cent So
luton of sulphuric acid. The lead
body Of a storage battery plate simply
acts as q holder OF c%ontainer for the
active material. The active materials
in q 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 discharg-
ing. that is, while a current is being
drawn from II, a 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 sulphste and water. Acid
Is more dense than water, so that
when fully charged the electrolyte has
q density of 1.275 to 1900, which
means that the electroIyte is 1.275 to
l9 times as heavy as an equal volume
Of water. AS the battery is discharged
and water is formed by the chemical
action, the eIectrolyte becomes less
dense. Finally, when the density
drops to 100 to 1.150, the battery
reaches a point when charging is nee
essary. Thus the density Of the cleo
trolyte is a measure Of how much en-
ergy, or how fully charged the bat
terry Is.
The voltage Of a battery is also
an indication Of the degree of charge.
A fully charged battery should have
an open circuit voltage Of % volts
per cell.
The voltage per cell should not be
allowed to drop below 1S before re-
Charging.
when a storage battery is put on
charge, a 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 lay,
the lead sulphate and water formed
during the discharge are converted
back into lead peroxide and sulphuric
acid. The formation Of %sulphuric
acid during the charging process
causes the density of the electrOlyte
to increase. The density of the cleo
trolyte of a fully charged battery is
between 1915 and 1900. while the
open circuit voltage per cell Is about
%.
OF 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
pere hours drawn from the 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 fact that some OF
the lead sulphate is not readily con
verted into lead peroxide and sui
phuric acid, 1t Is necessary at time:
TO give the battery an over
charge. That is, the charging cur
rent should be allowed to flow aftel
the battery has reached the charged
condition, until after several hours o
constant charging, there is nc In
crease In the voltage per cell or thu
density OF the electrolyte.
The value of the charging curren
Is determined by the manufactures
and should not be exceeded. An ez
cessively high charging current vii
cause an Increase in the rate Of de
teriOrstion Of the plates. Every tim
q battery is charged or discharged
certain amount of active material o.
the plates crumbIes and drops to tn
bottom Of the cell.
Assuming the same operating cor
ditions, the life of a storage battery /
Il tcFthtu uullUcT u CHAE&CS anu uAs
charges. An excessive rate of charg
or discharge will cause the battery
heat, buckle the plates, and result
an abnormal amount of crumbling
the active material. In the extrem
case Of q short circuit, the plates c
the battery might be buckled to sue
an extent that an internal short eli
cult is formed in the battery. 7
guard against short circuits 1t is we
when using a lead plate storage ba
terry to install a fuse IN both batter
leads right ear the terminals Of tn
ARTERY. Don't under any coBditio
spark the battery by placing 3 pa
of pliers or a screw driver across q
terminals. This will eventually rus
the battery.
'fhe water Will eyapOrafe ont uf 9h
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