Yanmar 3YM30 Sevice Manual page 44

2. Inspection and adjustment
(b) Measurement with hydrometer
When using a hydrometer, the measured specific
gravity must be corrected according to the temperature
at the time of measurement. The specific gravity of
battery electrolyte is defined with 20
Since the specific gravity increases or decreases by
0.0007 when the temperature varies by 1
value according to the equation below.
S = St + 0.007 ( t - 20 )
20
Specific gravity at measurement
Converted specific gravity at 20 C
Specific gravity and remaining battery charge
Specific Discharged quantity
gravity of electricity
(20°C)
1.28
1.26 10
1.24 20
1.23 25
(3) Terminals
Clean if corroded or soiled.
(4) Mounting bracket
Repair or replace it if corroded.
Retighten if loosened.
(5) Battery appearance
Replace the battery if cracked or deformed.
Clean with fresh water if contaminated.
C as the standard.
°
C, correct the
°
Electrolyte temperature
at measurement
Remaining charge
(%)
0 100
90
80
75
Battery charge measurement
(
with a hydrometer
Rubber bulb
Glass tube
(%)
(Hydrometer structure)
(How to read hydrometer)
29
Float
)
Float