2008 Yamaha Raptor 250SE / 250SE2 Factory Service Manual, Page 107Get this manual
CHECKING AND CHARGING THE BATTERY
Example cOpen-circuit voltage12.0 dCharging time6.5 hours eCharge of the battery2030
Charging Open-circuit voltage (V) 18 17 16 15 14 13 12 11 10
Ambient temperature 20C (68F)
5Charge: battery (refer to the appropriate charging method illustration)
WARNING