Generac Power Systems GTV-990 Manual page 42

SECTION 7: ALTERNATORS
TESTING REGULATOR-RECTIFIER:
1. Using a digital multimeter, test the battery voltage while
the engine is NOT running.
2. With the charging system properly connected, start the
engine.
3. Bring the engine up to normal operating speed and test
the battery voltage again.
4. If the battery voltage while the engine is running is greater
than when the engine is stopped, the charging system is
working.
Note: With the engine running, the battery voltage
should be at least 13 Volts.
BATTERIES
Note: See Section 6 for battery size and cable selection
information.
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