Yamaha CS50 Service Manual page 58

CHECKING AND CHARGING THE BATTERY
Charging method using a variable-current (voltage) charger
YES
Adjust the voltage so that the
current is at the standard
charging level.
Set the time according to the
charging time suitable for the
open-circuit voltage.
Refer to "Battery condition
checking steps.
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.
Measure the battery open-circuit voltage after 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
Measure the open-circuit
voltage prior to charging.
Connect a charged and
AMP meter to the battery
and start charging.
Make sure that the current
is higher than the standard
charging current written on
the battery.
YES
3-28
CHK
ADJ
NOTE:
Voltage should be measured 30 minutes after the
machine is stopped.
NOTE:
Set the charging voltage at 16 ~ 17 V. (If the set-
ting is lower, charging will be insufficient. If too
high, the battery will be over-charged.)
NO
By turning the charging
voltage adjust dial, set the
charging voltage at 20 ~ 24 V.
Monitor the amperage for
3 ~ 5 minutes to check if the
standard charging current is
reached.
NO
If the current does not
exceed the standard
charging current after 5
minutes, replace the battery.