Ei Omega 600W Alternator Upgrade Kit with 107mm Stator for Airheads 1977-On EXCEPT R100's
600W Omega Charging System Kit by Ei with 107mm Stator
This is the most powerful Airhead charging system on the market, and it will not let you down even when pulling significant amps caused by power hungry accessories like additional driving lights and heated clothing.
See the impressive output numbers from Robert Fleisher's (aka Snobum) testing, published on his website bmwmotorcycletech.info:
... the battery was heavily loaded (typically 40, 50, and 90 amperes). This especially was so for wherever you see the SAME RPM being used. Below table is for the tests on the "600" (Ei 600 Watt System) with the new battery; note that VR (Voltage Regulator) set point is 14.08v, warm.