Yamaha YFM660RN Service Manual page 109

CHECKING THE BATTERY
Check the condition of the battery using the
following charts.
Example:
Open-circuit voltage = 12.0 V
Charging time = 6.5 hours
Charge condition of the battery = 20 ~ 30%
Charging method for MF batteries
CAUTION:
If it is impossible to set the standard
charging current, be careful not to over-
charge.
When charging the battery, be sure to
remove it from the motorcycle. (If charg-
ing has to be done with the battery
mounted on the motorcycle, be sure to
disconnect the wire at the negative termi-
nal.)
Never remove the sealing caps of an MF
battery.
Make sure that the charging clips are in
full contact with the terminal and that they
are not shorted together. (A corroded clip
on the charger may cause the battery to
generate heat in the contact area. A weak
clip spring may cause sparks.)
Before removing the clips from the bat-
tery terminals, be sure to turn off the
charger's power switch.
The open-circuit voltage variation for the
MF battery, after charging, is shown
below. As shown in the figure, the open-
circuit voltage stabilizes about 30 min-
utes after charging has been completed.
Therefore, wait 30 minutes after charging
is completed before measuring the open-
circuit voltage.
***********************************************
3 - 53
CHK
ADJ