Eu encontrei as instruções originais em esta página .
After approx. 3 hours of charging, the battery will be sufficiently charged for use in regular applications. After approx. 8-10 hours of charging, the battery will be fully charged.
Depois de algumas linhas, diz:
After normal use, a charging time of 3 hours will provide sufficient power for most applications. However, further charging for up to 6 hours could significantly increase the use time, depending on the battery and charging conditions.