Checking Electrolyte Specific Gravity; Charging - Kohler 8.5RMY Operation And Installation Manual

3.8.3 Checking Electrolyte Specific
Gravity
Use a battery hydrometer to check the specific gravity of
the electrolyte in each battery cell.
hydrometer's test instructions, if available, or Figure 3-9
for bead-type testers.
Temperature affects specific gravity; correct the
indicated hydrometer readings for temperature. If the
hydrometer does not have a correction table, use
Figure 3-10. A fully charged battery should have a
specific gravity of 1.260 with the electrolyte at 26.7_C
(80_F). Charge the battery if the specific gravity from
cell to cell varies by more than 0.01. Charge the battery
if the specific gravity is less than 1.215 with the
electrolyte at 26.7_C (80_F).
3.8.4

Charging

Use a battery charger to maintain a fully charged battery
when the generator set is used in a standby application.
The engine battery-charging system charges the
battery while the generator set is running.
Number of
Beads Floating Condition
5 Overcharged
4 Full Charge
3 Adequate Charge
1, 2 Low Charge
0 Battery Dead
Figure 3-9 Electrolyte Testing Chart
16 Section 3 Scheduled Maintenance
Use the
Battery
° °
Correction
C F
71.1 160 + .032
+ .030
65.6 150 + .028
+ .026
60.0 140 + .024
+ .022
54.4 130 + .020
+ .018
48.9 120 + .016
+ .014
43.3 110 + .012
+ .010
37.8 100 + .008
+ .006
32.2 90 + .004
+ .002
26.7 80 0
-- .002
21.1 70 -- .004
--. 006
15.6 60 -- .008
-- .010
10 50 -- .012
-- .014
4.4
40 -- .016
-- .018
-- 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 5.5°C (10°F) change in electrolyte
temperature.
Figure 3-10 Specific Gravity Temperature Correction
Example 1:
°
Temperature below 26.7 C (80
Hydrometer Reading 1.250
Electrolyte Temperature
° °
--6.7 C (20 F)
Subtract .024 Specific Gravity
Corrected Specific Gravity is 1.226
Example 2:
°
Temperature above 26.7 C (80
Hydrometer Reading 1.235
Electrolyte Temperature
° °
37.8 C (100 F)
Add .008 Specific Gravity
Corrected Specific Gravity is
1.243
5810322
TP-6049 9/02
°
F)
°
F)