Yamaha RS90GTZ Service Manual page 79

BATTERY INSPECTION
3. Disconnect:
• Battery leads
(from the battery terminals)
NOTICE
First, disconnect the negative battery lead
, then the positive battery lead
4. Remove:
• Battery
5. Inspect:
• Battery charge
Inspection steps:
• Connect a analog packet tester (pocket
tester) to the battery terminals.
Positive tester probe →
Negative tester probe →
TIP
• The charge state of a VRLA (Valve Regulated
Lead Acid) battery can be checked by mea-
suring its open-circuit voltage (i.e., the voltage
when the positive terminal is disconnected).
• No charging is necessary when the open-cir-
cuit voltage equals or exceeds 12.8 V.
• Check the charge of the battery, as shown in
the charts and the following example.
Example
• Open-circuit voltage = 12.0 V
• Charging time = 6.5 hours
• Charge of the battery = 20 ~ 30%
Open-circuit voltage (V)
Charging time (hours)
Relationship between the open-circuit voltage
and the charging time at 20 °C (68 °F)
These values vary with the temperature, the
condition of the battery plates, and the electro-
lyte level.
Time (minutes)
Charging
Ambient temperature 20 °C (68 °F)
Check the open-circuit voltage.
Charging condition of the battery (%)
2-56
INSP
ADJ
.
positive battery terminal
negative battery terminal