TM 5-4930-218-14
minutes. Stop the engine and check the batteries with a
(2) Flush the metallic parts with a solution of
water and baking soda to neutralize any spilled acid.
hydrometer. A fully charged battery shall have a
minimum specific gravity of 1.275 at 75F (24C)
NOTE
(TM 9-2610-200-20).
Do not mix or match military
(3) If the specific gravity of the electrolyte is less
batteries and maintenance-free
than 1.250, the batteries must be charged before use.
batteries. Uneven charging will
When you charge the battery, use a constant current
result.
charger. Check the specific gravity of the electrolyte
(3) Inspect the batteries for cracks, loose
every 30 minutes. The batteries are fully charged
terminals, and other damage. Replace damaged
when you get a constant specific gravity reading for
batteries.
three 30-minute intervals.
(4) Inspect the battery cables for corrosion,
CAUTION
damaged clamps, broken cable strands, and
deteriorated or abraded insulation. Replace if
Constant-current battery charging
damaged.
is always preferred. If you must use
(5) If necessary, service the batteries (TM
a constant-potential charger,
9-2610-200-20).
battery temperatures must be
maintained at less than 130F
and install the batteries and cables in the reverse order
( 5 4 C ) by interrupting the
of removal. After installation, be sure that you coat the
c h a r g i n g procedure as this
battery terminals with GAA lubricant or petroleum
temperature is approached.
jelly to prevent corrosion. Be sure the negative cable is
(4) During charging, check the electrolyte level
connected to ground and that the positive cable is
frequently. Add distilled water when necessary to
connected to the starter terminal.
maintain the battery electrolyte level. Continue
4-24. Starting Motor
charging after adding water to assure proper mixing of
a. Starting Motor Checkout. If the starting motor
the solution.
fails to crank the engine, first check to make sure that
(5) Charge the batteries a minimum of once each
the engine crankshaft is free and that the engine is not
month when the batteries are not in service. if the
seized. If the engine turns over without application of
batteries fail to take or maintain a charge, replace them.
excessive force, use a DC voltmeter to check that 24
b. Removal.
volts is applied to the starting motor when the
(1) Pull out the battery drawer, disconnect the
STARTER pushbutton is pressed. If the starting motor
connector cable (1, fig. 4-2), battery cable (10), and
fails to rotate the engine with the correct voltage
ground cable (9) form the batteries. Disconnect the
applied, replace the starting motor.
opposite ends of the cables and remove them form the
b. Removal.
lubricating and servicing unit.
(1) Disconnect and tape the positive battery cable
(2) Remove the four cap screws (12), nuts (13),
from the battery terminal. This is necessary to prevent
and lock washers (14) that secure the two battery
shorting of the engine electrical system.
tiedowns (15) to the battery drawer (18). Lift the
batteries form the drawer.
(2) Tag and disconnect the starting motor
c. Cleaning and Inspection.
electrical leads.
(3) Remove the two cap screws (36, fig. 4-4) that
(1) Clean the battery tops and the cable ends with
secure the starting motor (37) to the engine; pull
a solution of water and baking soda to neutralize any
straight out on the starting motor to disengage the
acid on the parts, Prevent the solution from entering
pinion from the engine ring gear.
the battery.
Change 2
* U.S. GOVERNMENT PRINTING OFFICE 1991 554-123/20128
