Hi.  Are you connecting the charger to the bike correctly?  On the bike there is a very tiny notch in the receptacle through which the 
corresponding piece from the charger side slides; after which you tighten the connection "ring" by turning it clockwise.  If this isn't what's
causing your problem, contact Haromtb at 800-289-4276.  Also ask them about getting an adaptor to be able to charge the battery off the
bike.  Hope this helps.