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Controls and Operation
OUOD006,0000057 –19–17AUG04–1/1
Checking Battery State-of-Charge
TYK275 –UN–08OCT96
Checking State-of-Charge
A—Hydrometer
Use a voltmeter or hydrometer (A) to determine state-of
charge. Refer to chart to obtain percent of charge.
Voltmeter Reading Hydrometer Battery Test
Reading Reading
12 Volt Battery* Specific Gravity Percent of Charge
12.4 or greater 1.265 100%
12.39 to 12.25 1.225 75%
12.24 to 12.10 1.190 50%
12.09 to 11.96 1.155 25%
11.95 to 0 1.120 0%
* 6 volt battery voltmeter readings are one-half of 12 volt
battery readings shown.
CAUTION: Do NOT attempt to charge a frozen
battery.
NOTE: Any battery 25% charged or less may readily
freeze and should be charged at once.
OUOD006,0000059 –19–18AUG04–1/1
Identifying Battery Reserve Capacity (RC) Rating
Typical Group Sizes Auto, LGC, etc. 3ET, 47, 48, 49 31, 30H 1, 2 5D, 4 4D, 3EH, 8D
Reserve Capacity 80 or less 81-125 126-180 181-260 261 or more
Rating
Time needed to completely recharge a battery
depends on the battery’s electrical capacity and
present state of charge. Battery electrical reserve (RC
rating) is given in minutes, and is needed when
estimating recharge time.
Most batteries have a label attached showing the
battery’s type and/or reserve capacity rating. If this
information is not found on the battery, use the above
chart to determine reserve capacity (RC) rating.
10-3
091604
PN=14