Service manual

ELECTRICAL
CONVENTIONAL BATTERY OCV - OPEN
CIRCUIT VOLTAGE TEST
Battery voltage should be checked with a digital
multitester. Readings of 12.6 volts or less require further
battery testing and charging. See charts and
Load Test on below.
NOTE: Lead-acid batteries should be kept at or near a full
charge as possible. Electrolyte level should be kept
between the low and full marks. If the battery is stored or
used in a partially charged condition, or with low electrolyte
levels, hard crystal sulfating will form on the plates, reducing
the efficiency and service life of the battery.
CONVENTIONAL BATTERY SPECIFIC
GRAVITY TEST
A tool such as a Battery Hydrometer can be used to
measure electrolyte strength or specific gravity. As the
battery goes through the charge/discharge cycle, the
electrolyte goes from a heavy (more acidic) state at full
charge to a light (more water) state when discharged. The
hydrometer can measure state of charge and differences
between cells in a multi-cell battery. Readings of 1.270 or
greater should be observed in a fully charged battery.
Differences ofmore than .025 between the lowest and
highest cell readings indicate a need to replace the battery.
OPEN CIRCUIT VOLTAGE
State of charge Conventional
Lead-acid
Low Maintenance
Type
100%
75% Charged
50% Charged
25% Charged
0% Charged
12.60V
12.40V
12.10V
11.8V
Less than
12.70V
12.50V
12.20V
12.0V
Less than 11.9V
SPECIFIC GRAVITY
State of charge* Conventional
lead-acid
Low Maintenance
Type
100%
75% Charged
50% Charged
25% Charged
0% Charged
1.265
1.210
1.160
1.120
Less than 1.100
1.275
1.225
1.175
1.135
Less than 1.115
* At 28℃
NOTE: Subtract .01 from the specific gravity reading at 0℃.
CONVENTIONAL BATTERY LOAD TEST
To prevent shock or component damage, remove
spark plug high tension leads and connect securely to
engine ground before proceeding.
NOTE: This test can only be performed onmachines
with electric starters. This test cannot be performed
with an engine or starting system that is not working
properly. A batterymay indicate a full charge condition
in the OCV test and the specific gravity test, but still
may not have the storage capacity necessary to
properly function in the electrical system. For this
reason, a battery capacity or load test should be
conducted whenever poor battery performance is
encountered. To perform this test, hook a multitester to
the battery in the same manner as was done in the
OCV test. The reading should be 12.6 volts or greater.
Engage the starter and observe the battery voltage
while cranking the engine. Continue the test for
15 seconds. During cranking the observed voltage
should not drop below 9.5 volts. If the beginning
voltage is 12.6 volts or higher and the cranking voltage
drops below 9.5 volts during the test, replace the
battery.
9.25