Yale MPB045VG, Operating Manual

Page: 66 / 76

Table 4. Specific Gravity Corrections
Specific
Gravity
Reading
Electrolyte
Temperature
Correction
Points
Correct
Value
1.210 31 °C
(87 °F)
+0.003 1.213
1.210 27 °C
(80 °F)
+0.001 1.211
1.210 25 °C
(77 °F)
+0.000 1.210
1.210 18 °C
(64 °F)
−0.004 1.206
+0.001 or −0.001 for each −16 °C (3 °F) from the 25 °C
(77 °F) Base Value.
(°C + 17.8) (1.8) + °F.
CAUTION
Low battery voltage requires higher current flow to do
the same work. This high current flow can damage the
motor, contactors, and the battery. Do not operate the
lift truck with a battery that has a corrected specific
gravity of less than the minimum value specified by the
manufacturer.
Proper use of the hydrometer and proper operation of the
charger are important. Follow the instructions of the manu-
facturer. See
Figure 15 .
Make specific gravity corrections for the electrolyte temper-
ature as shown in
Table 4 .
Remove the vent cap from each cell and make sure the
plates have electrolyte over them before charging the bat-
tery. Never charge a battery at a rate that will raise the
electrolyte temperature above 49 °C (120 °F). Never let a
battery stay completely discharged.
Each battery must have a slow rate charge (equalizer
charge) for 3 to 6 hours following a normal charge once
each month. DO NOT give an equalizer charge more than
once a week. If the specific gravity difference is more than
0.020 between cells of the battery after an equalizer
charge, consult your battery dealer.
Maintenance
64