Star CAPELLA - Hydrometer Usage; Hydrometer Usage and Safety

AC VOLTAGE / FAULT DIAGNOSIS HYDROMETER
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Read all of SAFETY and this section before attempting any procedure.
Pay particular attention to Notices, Cautions, Warnings and Dangers
HYDROMETER
A hydrometer is used to test the state of charge of a battery cell.
This is performed by measuring the density of the electrolyte, which
isaccomplishedbymeasuringthespecicgravityoftheelectrolyte.
The greater the concentration of sulfuric acid, the more dense the electrolyte
becomes. The higher the density, the higher the state of charge.
To prevent battery explosion, never insert a metal thermometer into a battery.
Use a hydrometer with a built in thermometer that is designed for testing batteries.
Specicgravityisthemeasurementof
a liquid that is compared to a base- line.
The baseline is water which is assigned
a base number of 1.0. The concentration
of sulfuric acid to water in a NEW golf car
battery is 1.280 times the weight of the
same volume of water. A fully charged
battery will test at 1.275-1.280 while a
discharged battery will read in the
1.140 range.
DO NOT perform a hydrometer test on a battery that has just been watered.
The battery must go through at least one charge and discharge cycle in order
to permit the water to adequately mix with the electrolyte.
The temperature of the electrolyte is important since the hydrometer reading
must be corrected to 80° F (27° C). High quality hydrometers are equipped with
an internal thermometer that will measure the temperature of the electrolyte
andwillincludeaconversionscaletocorrecttheoatreading.Itisimportant
torecognizethattheelectrolytetemperatureissignicantlydifferentfromthe
ambient temperature if the vehicle has been operated.
Bulb FloatCylinder
Thermometer
Add to Float
Reading
Subtract
from Float
Reading
Weight