Battery Care - Westerbeke 10.0 EGTD Operator's Manual

DC ELECTRICAL SYSTEM
7. Now check the voltage between the alternator output
ter-
minal
(B+)
and ground. If the circuit is good, the voltage at
the alternator will be the same as the battery, or if an isola-
tor is in
the circuit the alternator voltage will be zero.
If
neither of the above is true, a problem exists in the circuit
between the alternator and the battery. Check all the
connections -look for an opening in the charging circuit.
TESTING THE STARTING
BAmRY/ALTERNATOR
(ENGINE RUNNING)
MULTIMETER
ENGINE
,.c:::::o---1
GROUND
8. Start the engine again. Check the voltage between the
alternator output and ground.
The voltage reading for a properly operating alternator
should be between 13.5 and 14.5 volts. If your alternator
is over- or under-charging, have it repaired at a reliable
service facility.
NOTE: Before removing the alternator for repair, use a
voltmeter to ensure
that
12 volts DC excitation is present
at
the EXC tenninal
if
the previous test showed only bat-
tery voltage at the B output tenninal.
If
12 volts is not present
at
the EXC terminal, trace the
wiring and look for breaks and poor connections.
12 VOLT DC CONTROL CIRCUIT
The engine has a 12 volt DC electrical control circuit that is
shown on the wiring diagrams that follow. Refer to these
diagrams when troubleshooting or when servicing the DC
electrical system.
A
CAUTION:
To avoid damage to the battery charging
circuit, never shut off the engine battery switch while
. the engine is running. Shut off the engine battery switch,
however. to avoid electrical shorts when working on the
engine's electrical circuit.
BATTERY
The minimum recommended capacity of the battery used in
the engine's 12 volt DC control circuit is 600- 900 Cold
Cranking Amps (CCA).
Checking the Service Battery
Check the voltage of the service battery. This battery should
have a voltage between 13 and 14 volts when the engine is
running. If not, there is a problem in the service battery
charging circuit. Troubleshoot the service battery charging
circuit by checking the wiring and connections, the solenoid,
isolator, battery switch, and the battery itself.
GROUND
,SERVICE BATTERY
TESTING THE SERVICE
BAnERY (ENGINE RUNNING)
A
CAUTI,ON:
To avoid damaging the alternator
diodes~
do not use a high voltage tester (I.e. a megger) when
perfonnlng tests on the alternator charging circuit.
Battery Care
Review the manufacturer's recommendations and then
establish a systematic maintenance schedule for your
engine's starting batteries and house batteries.
0
Monitor your voltmeter for proper charging during
engine operation.
0
Check the electrolyte level and specific gravity with a
hydrometer.
0
Use only distilled water to bring electrolytes to a proper
level.
0
Make certain that battery cable connections are clean and
tight to the battery posts (and to your engine).
0
Keep your batteries clean and free of corrosion.
22
A
WARNING:
Sulfuric acid in lead batteries can
causs severe burns on skin and damage clothing. Wear
protective gear.