Yamaha YFM250RX 2008 Service Manual page 107

CHECKING AND CHARGING THE BATTERY
Relationship between the open-circuit voltage
and the charging time at 20 °C (68 °F)
Charging time (hours)
These values vary with the temperature, the condition of
the battery plates, and the electrolyte level.
NOTE: NOTE:
Since MF batteries are sealed, it is not possi-
ble to check the charge state of the battery by
measuring the specific gravity of the electro-
lyte. Therefore, the charge of the battery has to
be checked by measuring the voltage at the
battery terminals.
1. Remove:
• seat
• battery cover
Refer to "SEAT, FENDERS AND FUEL
TANK".
2. Disconnect:
• battery leads
(from the battery terminals)
CAUTION:
First, disconnect the negative battery lead
, and then the positive battery lead
3. Remove:
• battery
4. Check:
• battery charge
a. Connect a pocket tester to the battery ter-
minals.
Positive tester probe →
Negative tester probe →
NOTE: NOTE:
• The charge state of an MF battery can be
checked by measuring 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.
b. Check the charge of the battery, as shown
in the charts and the following example.
3-46
CHK
ADJ
positive battery terminal
negative battery terminal
.