TM 5-684/NAVFAC MO-200/AFJMAN 32-1082
any given voltage, the battery charger will always
(3) Check the operating temperature of equip-
ment, (by touch)
deliver a given current and vice versa. This slope
(4) Check the operating voltage of voltage-
characteristic is inherent in the battery charger and
is not affected by the size or type of battery. It
(5) Check the operation of timers.
simply responds to the counter-voltage of the bat-
(6) Check that all meters are at zero calibra-
(1) Battery charger suitability. The battery
b. Potential testing. Whenever checking circuits
charger, if properly designed, will have a slope char-
or components, do not test with a megohmeter of
acteristic compatible with the battery it is charging.
any potential higher than the voltage of the equip-
2. Checking of the battery charger slope. In the
ment which is being tested. Any higher voltage may
event of any apparent improper operation, the bat-
break down rectifying elements or insulation not
tery charger slope characteristics should be
designed to withstand it.
checked. If actual readings of voltage and current
c. Slope characteristic. Every battery charger has
fall on or reasonably near the slope line, the battery
a relationship between the output voltage and the
charger is not at fault and the trouble is elsewhere.
output current throughout its complete range. For
Section VIII-PLACING A NEW BATTERY IN SERVICE
14-24. Placing lead-acid batteries in service.
the battery in service to ensure that the proper
electrolyte is used and that the battery is properly
Most lead-acid batteries are manufactured as wet-
charged. The furnished electrolyte will probably
charged units. However, vented (flooded) batteries
have a specific gravity about 10 points lower than
can be ordered as dry-charged units, when it is
the nominal full charge specific gravity of the bat-
desirable to store them for a considerable period
before they are put in use.
a. Wet-charged batteries. Wet-charged lead-acid
(2) Freshening charge. It is a good practice to
batteries contain fully-charged elements and are
slow charge a freshly-activated battery. This en-
filled with electrolyte at the time of manufacture. A
sures a fully-charged battery. Always charge a
wet-charged battery will not maintain its charged
newly-activated battery for at least an hour. Once it
condition during storage, and must be recharged
has been properly prepared and installed, a dry-
periodically even if not used. Upon receipt of a bat-
charged battery will have the capacity, characteris-
tery, it is recommended that it be given an initial
tics, and the life of a similar wet-charged battery.
charge for a period of from 3 to 6 hours. Charge
until there is no rise in the specific gravity. Use the
14-25. Placing nickel-cadmium batteries in
finishing rate as indicated in the specific battery
instructions or on the battery nameplate. Cell tem-
Batteries will generally be supplied "filled and dis-
perature during charge should not exceed 110 de-
charged", but "filled and partially charged" units
grees F (43 degrees C). Should the temperature
can be provided. Either type should be capable of
become excessive, the charging rate should be de-
being stored for up to one year without a recharge.
b. Dry-charged batteries. A dry-charged battery
Vented (flooded) units can also be provided as "dis-
contains fully-charged elements, but it contains no
charged and empty" and can be stored indefinitely.
electrolyte until it is activated for service. It leaves
All vented batteries must be firmly fitted with vent
the manufacturer in a dry state. Once activated, it
plugs during transit. Check plugs periodically to
is essentially the same as a wet-charged battery. At
ensure integrity of the seals. Charging during stor-
the time of manufacture, the battery elements are
age, charging prior to putting in service, and filling
charged by a direct current being passed through
empty cells should be done in accordance with the
the plates while they are immersed in an electrolyte
manufacturer's instructions and using the manufac-
of dilute sulfuric acid. The fully-charged plates are
then removed from the electrolyte, washed in water,
and completely dried. The battery is then as-
14-26. Connections for batteries.
sembled. A dry-charged battery retains its state of
Clean all points of electrical contact to be certain of
full charge as long as moisture is not allowed to
good conductivity through terminal connections. If
enter the cells.
(1) Filling. Most manufacturers furnish a
connections are copper, apply a coat of petroleum
packaged electrolyte and instructions for placing
jelly (such as Vaseline) to prevent corrosion.