Gravely 988001, Service Manual

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Clean Battery
Corrosion and dirt on the battery and terminals can
cause the battery to "leak" power.
• Remove battery. (See Battery Removal and
Installation)
• Rinse the battery with plain water and dry.
• Clean terminals and battery cable ends with wire
brush until bright.
• Coat terminals with grease or petroleum jelly.
• Reinstall battery.
Inspection, Cleaning, Drying, and Maintenance
Inspect the top of battery, terminals, cables, terminal
posts, and case for any accumulation of dirt, corrosion
cracks or loose or broken parts. Keep battery and its
terminals clean. Inspect monthly to maintain best
performance. Replace battery if damaged.
Remove hold down and bolt and lift battery out. Clean
or service battery away from unit. Remove corrosion
from battery terminals and cable connections with wire
brush, then wash with a weak baking soda solution.
Scrub the exterior of the battery and cable terminals
with a nonmetallic brush which has been dipped into a
mixture of baking soda and water.
After cleaning, apply a thin coat of grease or petroleum
jelly to terminals and cable ends to retard corrosion.
Reinstall battery.
Check the alternator voltage regulator output (if used)
at every periodic maintenance inspection. Over
charging is a common cause of battery failure.
Electrolyte Level
Every 25 hours of operation, check electrolyte level of
each cell by removing caps one at a time. The
electrolyte level should be at level indicated. Use
distilled water to fill each cell if needed. Install and
tighten each cap after checking.
IMPORTANT: When distilled water is added to battery
during freezing weather, battery must be charged to
mix water with electrolyte, or water will remain at top
and freeze.
Charging
ALWAYS follow information provided on battery by
battery manufacturer. Contact battery manufacturer for
extensive instructions to charge battery.
Place unit on a level surface, shut off engine and open
battery compartment to gain access to battery.
Disconnect negative (-) cable first, then positive (+)
cable.
To charge battery:
1. Loosen strap and remove battery from unit.
2. Place battery on bench or other well ventilated
place where electrolyte spill will not create
damage.
3. Remove caps and fill each cell to level indicated
with electrolyte at 1.230 specific gravity and 80
o
F
(27
o
C).
4. Let battery stand for one half hour.
5. Check electrolyte level and add more if necessary.
6. Connect positive (+) lead of charger to positive (+)
terminal, and negative (-) lead to negative (-)
terminal.
7. Charge the battery at two and a half amps for ten
hours or until all cells are gassing freely and the
specific gravity is constant over three 30 minute
intervals.
Specific Gravity Check
The specific gravity should be checked with a
hydrometer.
NOTE: The specific gravity should be checked in each
cell and should be the same for all cells. A variation in a
cell reading could be an indication of a problem. Sub-
tract .004 from 1.265 for each 10
o
F below 80
o
F (27
o
C)
or add .004 to 1.265 for each 10
o
F above 80
o
F (27
o
C).
A special temperature compensated hydrometer is
used to read the battery’s state of charge.
The reading on the hydrometer gauge should be above
1.225. If the reading falls below 1.225 specific gravity
there will be an insufficient charge.
ALWAYS charge the battery until the specific gravity of
1.265 is reached over 3 successive readings. Check
monthly to ensure charge is maintained. The
approximate state of charge can be determined by the
cell specific gravity of the rested open circuit voltage at
room temperature and the charging time can be
estimated. For example:
If using an automatic tapering 12 volt charger, choosing
a good quality 5 to 10 amps 15VDC minimum output
charger and charge for 3 to 12 hours according to the
battery state of charge (see table above) or until the
specific gravity in each cell reaches 1.255 - 1.265
specific gravity at 80
o
F (27
o
C).
If using a constant current charger, charge at 1 to 2
amperes for the time given on the table above or until
full specific gravity is reached.
OCV Specific
Gravity
% of
Charge
Charging
Time
12.60 1.265 100% ---
12.4 1.225 75% 3 hours
12.20 1.180 50% 7 hours
12.00 1.130 25% 10 hours
11.80 1.100 0% 12 hours