ELECTRICAL AND ECU
Battery Components and Functions
12-4
6LY3 Service Manual
© 2007 Yanmar Marine International
Overall length of the cables between the battery
terminals and the starter terminals should be
determined according to the following table:
High resistance in the key switch
(Figure 12-3, (2))
circuit can cause weak starter pinion engagement.
Figure 12-3
Figure 12-3
1 – Battery Switch
2 – Key Switch
3 – Starter Motor
4 – Battery
Inspecting the Battery
The strength of the battery’s charge governs the
starting performance of the engine. Inspect the
battery routinely to ensure dependable starting
performance.
Visual Inspection
1. Inspect the case for cracks, damage and
electrolyte leakage.
2. Inspect the battery holder for tightness,
corrosion and damage.
3. Inspect the terminals for corrosion and check
the cables for damage.
4. Inspect the caps for cracking, electrolyte
leakage and clogged vent holes. Correct any
abnormal conditions that are found. Clean
corroded terminals with a wire brush before
reconnecting the battery cable.
Checking the Electrolyte Level
Check the electrolyte level every 7 to 10 days. The
electrolyte must always be 10 to 20 mm (0.4 to
0.8 in.) over the top of the plates.
Figure 12-4
Figure 12-4
NOTICE:
1. The “LEVEL” line on a transparent plastic
battery case indicates the height of the
electrolyte.
2. Always use distilled water to replenish the
electrolyte level.
3. If electrolyte leaks from the battery, replace the
battery.
Measuring Electrolyte Specific Gravity
1. Draw some electrolyte up into a hydrometer.
2. Take the specific gravity reading at the top of
the scale of the hydrometer.
Figure 12-5
Figure 12-5
3. The battery is fully charged if the specific
gravity is 1.260 at an electrolyte temperature of
20°C (68°F). The battery is discharged if the
specific gravity is 1.200 (50%). If the specific
gravity is below 1.200, recharge the battery.
Battery Cable Specifications
Voltage
Voltage
Drop
Cross Section
a + b + c
Length
12V
0.2V or less
20 mm
2
(0.031 sq. in.)
3.5 m (11 ft)
40 mm
2
(0.062 sq. in.)
7 m (23 ft)
B
S
E
(4)
(1)
(2)
(
3
)
a
c
b
0006
3
51
000626
3
0006264
