forming room is put through several discharges and
charges after the battery is fully assembled. In service on a car, the
battery is being "cycled" constantly and there is generally an
increase in capacity after a battery is put on a car. Positive plates
naturally increase in capacity, sometimes up to the very clay when
they fall to pieces, while negatives tend to lose capacity with age.

Batteries which are assembled in the service station, using new
plates, generally require several cycles of charge and discharge
before the specific gravity will rise to 1.280 before the positives
will give 2.4-2.5 volts on a Cadmium test, before the negatives will
give a reversed voltage reading of 0.175 to 0.20 volt on a Cadmium
test, and before a satisfactory "starting-ability" or "breakdown" test
can be made.

A battery which has been abused by failing to add water to replace
evaporation, by allowing to remain in a partially or completely
discharged condition for sometime, or which has been allowed to become
sulphated in any other way, will generally require "cycling" before it
will "come-up" to a serviceable condition.

The rates for a "cycling" discharge should be such that the battery
will be discharged during the daytime, the discharge being started in
the morning, and the battery being put back oil the charging line in
the evening in order that it may be charging during the night. The
rate of discharge should be somewhat higher than the rate used when
the plates are formed. Two or three amperes per positive plate in each
cell will generally be satisfactory.

Discharge Apparatus

A simple discharge rheostat is shown in Fig. 180. The terminal on the
end of the cable attached to the right hand terminal of the battery
shown in the illustration is movable, and it may be clamped at any
point along the coils of wire so as to give various currents. The wire
should be greased lightly to prevent rusting.

[Fig. 180 Simple high rate discharge rheostat]

Another simple apparatus consists of a board on which are mounted six
double contact automobile lamp sockets which are all connected in
parallel. A pair of leads having test clips attached is brought out
from the sockets for fastening to the battery terminals. Lamps of
various candlepower may be turned into the sockets to obtain different
currents.

Discharge tests are helpful in the case of a battery that has lost
capacity. The battery is first fully charged, and is then