Checking Specific Gravity - Kohler 6.5RMY Operation Manual

It is not possible to check the specific gravity of a
maintenance free battery. Use a battery hydrometer to
check the specific gravity of the electrolyte in each
battery cell. While holding the hydrometer vertical, read
the number on the glass bulb at the top of the electrolyte
level. Use the correction table in Figure 3-3 if the
hydrometer used does not have a correction table.
Determine specific gravity and electrolyte temperature
of battery cells. Locate temperature in Figure 3-3 and
adjust specific gravity by amount shown. The battery is
fully charged if the specific gravity is 1.260 at an
electrolyte temperature of 80° F (26.7° C).
difference between specific gravities of each cell should
not exceed ±0.01. The battery should be charged if the
specific gravity is below 1.215 at an electrolyte
temperature of 80° F (26.7° C).
TP-5631 7/96

Checking Specific Gravity

The
Correction
° °
C F
71.1 160 + .032
+ .030
65.6 150 + .028
EXAMPLE NO. 1
+ .026
Temperature below 80
60.0 140 + .024
(26.7
+ .022
Hydrometer Reading 1.250
54.4 130 + .020
Acid
+ .018
(-6.7
48.9 120 + .016
+ .014
Subtract .024 Sp. Gravity
43.3 110 + .012
Corrected Sp. Gravity is 1.226
+ .010
37.8 100 + .008
+ .006
32.2 90 + .004
EXAMPLE NO. 2
+ .002
Temperature
26.7 80 0
(26.7
- .002
21.1 70 - .004
Hydrometer Reading 1.235
-. 006
15.6 60 - .008
Acid
- .010
(37.8
10 50 - .012
- .014
Add .008 Sp. Gravity
4.4 40 - .016
Corrected Specific Gravity is
- .018 1.243
- 1.1 30 - .020
- .022
- 6.7 20 - .024
- .026
- 12.2 10 - .028
The temperature correction amounts to about .004 (4 points) of
°
specific gravity for each 10 F (5.5
Figure 3-3. Specific Gravity Temperature
Correction
°
F
°
C)
°
Temperature 20 F
°
C)
°
above 80 F
°
C)
°
Temperature 100 F
°
C)
°
C) change in temperature.
Scheduled Maintenance 3-5