Yamaha WR250R Service Manual page 341

tery cool before reconnecting it. Hot
batteries can explode!
As shown in the following illustration, the
G
open-circuit voltage of an MF battery stabi-
lizes about 30 minutes after charging has
been completed. Therefore, wait 30 min-
utes after charging is completed before
measuring the open-circuit voltage.
A
A. Open-circuit voltage
B. Charging the open-circuit voltage
C. Temperature 20°C
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
Charging method using a variable-current
(voltage) charger
a. Measure the open-circuit voltage prior to
charging.
NOTE:
Voltage should be measured 30 minutes after
the machine is stopped.
b. Connect a charged and AMP meter to the
battery and start charging.
NOTE:
Set the charging voltage at 16–17 V.If the setting
is lower, charging will be insufficient. If too high,
the battery will be over-charged.
c. Make sure that the current is higher than the
standard charging current written on the bat-
tery.
NOTE:
If the current is lower than the standard charging
current written on the battery, set the charging
voltage adjust dial at 20–24 V and monitor the
amperage for 3–5 minutes to check the battery.
Reach the standard charging current
Battery is good.
Does not reach the standard charging
current
Replace the battery.
C
B
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ELECTRICAL COMPONENTS
d. Adjust the voltage so that the current is at the
standard charging level.
e. Set the time according to the charging time
suitable for the open-circuit voltage.
Refer to "Battery condition checking steps".
f. If charging requires more than 5 hours, it is
advisable to check the charging current after
a lapse of 5 hours. If there is any change in
the amperage, readjust the voltage to obtain
the standard charging current.
g. Measure the battery open-circuit voltage af-
ter leaving the battery unused for more than
30 minutes.
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12.8 V or more --- Charging is complete.
12.7 V or less --- Recharging is required.
Under 12.0 V --- Replace the battery.
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
Charging method using a constant voltage
charger
a. Measure the open-circuit voltage prior to
charging.
NOTE:
Voltage should be measured 30 minutes after
the machine is stopped.
b. Connect a charger and AMP meter to the bat-
tery and start charging.
c. Make sure that the current is higher than the
standard charging current written on the bat-
tery.
NOTE:
If the current is lower than the standard charging
current written on the battery, This type of bat-
tery charger cannot charge the MF battery. A
variable voltage charger is recommended.
d. Charge the battery until the battery's charg-
ing voltage is 15 V.
NOTE:
Set the charging time at 20 hours (maximum).
e. Measure the battery open-circuit voltage af-
ter leaving the battery unused for more than
30 minutes.
12.8 V or more --- Charging is complete.
12.7 V or less --- Recharging is required.
Under 12.0 V --- Replace the battery.
LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL