Hydrometer - Ezgo 2012 TERRAIN 250 Owner's Manual

MAINTENANCE
Read all of this manual to become thoroughly familiar with this vehicle. Pay particular attention to all Notices, Cautions, Warnings, and Dangers.
ranty. Different manufacturers have different requirements. Consult the battery manufacturer or the manufacturer's rep-
resentative for specific requirements.
The second reason is to determine why a particular vehicle does not perform adequately. Performance problems may
result in a vehicle that runs slowly or in a vehicle that is unable to operate for the time required.
A new battery must mature before it will develop its maximum capacity. Maturing may take up to 100 charge/discharge
cycles. After the maturing phase, the older a battery gets, the lower the capacity. The only way to determine the capacity
of a battery is to perform a load test using a discharge machine following manufacturer's recommendations.
A cost effective way to identify a poorly performing battery is to use a hydrometer to identify a battery in a set with a
lower than normal specific gravity. Once the particular cell or cells that are the problem are identified, the suspect battery
can be removed and replaced. At this point there is nothing that can be done to salvage the battery; however, the individ-
ual battery should be replaced with a good battery of the same brand, type and approximate age.

HYDROMETER

5
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 specific 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 that could result in
severe personal injury or death, never insert a metal
thermometer into a battery. Use a hydrometer with a
built in thermometer that is designed for testing bat-
teries.
Specific gravity is the measurement of a liquid that is compared
to a baseline. The baseline is water which is assigned a base
number of 1.000. The concentration of sulfuric acid to water in a
new golf car battery is 1.280 which means that the electrolyte
weighs 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 float reading. It is important to recognize that the electrolyte temperature is
significantly different from the ambient temperature if the vehicle has been operated.
5 - 20
BULB
CYLINDER
THERMOMETER
Add to Float
Reading
Subtract
from Float
Reading
Hydrometer
FLOAT
WEIGHT