This task covers:
PERSONNEL REQUIRED: 2
Tool Kit, General Mechanics, Automotive
(Appendix B, Section Ill, Item 1)
Hydrometer (Appendix B, Section Ill, Item 7)
Main Engine Shutdown (see para 2-12.)
APU Shutdown (see para 2-16.)
Batteries contain sulfuric acid. They may also
contain explosive mixtures of hydrogen and oxygen
gases in each cell at all times. To avoid serious
injury, always wear face shield, goggles, safety
shoes, gloves and protective clothing when working
with batteries. Keep sparks, flames, burning
cigarettes or other ignition sources away at all
Do the following steps for each cell:
Never take hydrometer reading immediately after
water is added to cell. Water must be mixed com-
hydrometer readings are reliable.
Make sure hydrometer barrel and float are not
cracked and that float is clean. Draw in and expel
electrolyte in hydrometer several times to bring
hydrometer float and barrel to same temperature as
(1) Remove filler caps from battery.
(2) Draw electrolyte into hydrometer until bulb
is fully expanded and float Iifts free. Float
shouId not touch side, top or bottom
stopper of barrel.
(3) Hold hydrometer with surface of liquid in
barrel at eye level. Disregard curvature of
liquid at float stem and barrel. Read
specific gravity on float scale.
(4) Compare reading to following table. Fully
charged specific gravity of 1.265 corrected
to 80°F (26.7°C) is assumed.