2. Inspection and Adjustment
25
(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
°
C as the standard.
Since the specific gravity increases or decreases by
0.0007 when the temperature varies by 1
°
C, correct the
value according to the equation below.
Specific gravity and remaining battery charge
(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.
Specific
gravity
(20°C)
Discharged quantity
of electricity
(%)
Remaining charge
(%)
1.28
0
100
1.26
10
90
1.24
20
80
1.23
25
75
Float
Battery charge measurement
with a hydrometer
(
)
S
20
= St + 0.007 ( t - 20 )
Electrolyte temperature
at measurement
Specific gravity at measurement
Converted specific gravity at 20 C
(Hydrometer structure)
Float
Glass tube
Rubber bulb
(How to read hydrometer)
