b. If battery is found discharged 100 points below
b. Individual cells should be considered to be low
full charge, a starting failure may result, and a charge
when reading 40 points below the highest reading cell in
should be given. The amount of charge need be only
specific gravity (corrected for temperature and
sufficient to get the locomotive in service. The cause
electrolyte level), or 0.20 volts lower than the average
for the discharged battery should be determined and
cell when the battery is on charge.
corrected.
c. If low cells are not due to leaky jars or
c. A recharge may be started at any rate in
containers, or improper regulator setting, and an
amperes, up to three times the normal finishing rate.
equalizing charge fails to correct the trouble, trays
This high rate of charge may be continued until the
containing low cells should be replaced with suitable
voltage of the battery reaches 2.40 volts per cell or
spare trays.
approximately 76 volts for a 32-cell battery, or 134 volts
d. Trays with low cells which are removed for
for a 56-cell battery. The charge rate should then be
shopping, should be tagged to indicate the low cells and
lowered into the finishing rate, or to a rate below that, if
if possible, the cause of the trouble.
necessary to keep the electrolyte temperature under
e. Repaired trays, when returned, must be placed
110 F., or not to exceed 15 above surrounding
in their original position. This is to insure cell readings
temperature. This method will safely complete the
being in proper order throughout the life of the battery.
charge in a minimum length of time.
f. Battery record card should note trays sent in for
d. An equalizing charge is a continuation of a
repairs.
recharge, and should be given at the finishing rate or
slightly lower. Temperature limits mentioned previously
127. Temperature Hot Battery
should be observed. The equalizing charge should be
Under normal operating conditions the electrolyte
continued until all cells gas freely, and until the specific
temperature may run up to 15 F. higher than the
gravity and voltage of the lowest cells show no further
average atmospheric temperature surrounding the
increase over a period of four successive hourly
battery compartment. A greater difference may result
readings.
from the following causes:
e. A recharge may be given the battery only for a
a. A hot battery may be due to excessive
short while in order to start the engine. This is called a
overcharging or charging at too high a rate for too long a
"boost charge." The auxiliary generator on the
time. High charge rates are often due to the voltage
locomotive would be expected to complete the charge.
regulator being set too high, to yard charge rates which
f. Batteries left on charge over night, with no
are too high, or the battery may be in an unserviceable
attendant present, should be charged at from 1/4 to 1/2
condition.
of the finishing rate.
This will prevent excessive
b. Poor ventilation may also cause excessive
temperature and possible damage to the battery.
battery temperatures. Refer to paragraph 114.
c. When a battery is found to be operating at an
129. Identification of Individual Cells and Trays
excessive temperature every effort should be made to
a. In order to obtain dependable records, establish
locate the cause and correct the condition immediately.
a definite method for identifying individual cells and
d. When the regulator is checked, record on the
trays. Readings will then be recorded in their proper
battery record card the date and setting as found and
order, and can be used as a reference throughout the
left.
life of the battery.
b. Make the positive terminal cell, connected to the
128. Recharging
positive side of the auxiliary generator circuit, number
a. The charging equipment on the locomotive is
one.
designed to keep the battery in a fully charged condition.
c. Mark the tray containing this cell number one.
Improper voltage regulator settings or failure of
d. Number each subsequent tray in order, following
equipment may result in a partly or completely
the series circuit of the battery.
discharged battery. Recharging of the battery from an
outside source or in the battery shop may then be
necessary.
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