Grip Heaters: This heater fits over the handlebar and fastens with a sheet metal screw for easy removal. Double wound heating coil eliminates resistors. Only 30 watts on high and 20 watts on low current draw. Handlebar Heaters: Why have cold hands? Polly Heaters can be installed on any machine having hollow handlebars and an electrical system capable of supporting a current draw of 3 amperes at 12 volts. Works with or without a battery.