Gilera SATURNO BIALBERO 350 Workshop Manual page 111

BATTERY CHARGING CIRCUIT 16
WARNING
The electrolyte level must be checked periodically; top up with distilled
water if necessary.
Remove the battery from the frame when charging.
Keep battery away from sparks and flames due to the hydrogen produced
by the battery.
All charging components may be tested without removal.
CHARGING CIRCUIT
Leak checks
Check for current leaks prior to the regulated voltage check.
Turn ignition switch to "OFF."
Disconnect the battery's ground cable.
Connect the ammeter between the ground cable and the negative (-) post
on the battery. The ammeter must have a reading of 0 A with the ignition
in the off position.
Charge circuit check
Make sure the battery is in working order before proceeding with this
operation.
Warm the engine up.
Remove seat.
Connect the voltmeter (fig. 2 [above]).
Keep engine running at idle.
Slowly increase engine speed.
Voltage should read between 13.5 and 14 V, if not, check for broken or
disconnected wires; if the wires are in good condition then replace the
regulator/rectifier and execute the same check again.
If voltage reading is still not correct, check the alternator stator coil.
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