The Battery Genuis

Charging Motorcycle Batteries A fully-charged 12-volt motorcycle battery should measure about 12.6 - 13.5 volts between terminals depending upon its chemistry. 12-volt motorcycle batteries supply useful energy only through a limited voltaic range -- from over 14 volts (when fully charged and rested) down to 10.5 volts in use/under load (this battery is noticed when your lights dim, or your motorcycle is hard to start). No 12-volt battery will remain at over 14 volts for more than a f …