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There don't seem to be any strong lights which can operate on only 50mA. The headlight with the lowest found current still required 750mA, although it could operate on 9V says it operates at 9-32V and would cost 300$US for the pair. [http://www.customdynamics.com/trubeam_motorcycle_led_headlamp.htm#7_L.E.D._Halo_Headlight_Trim_Ring_With_Built_In_Turn_Signals, scroll to TruBEAM 4.5" Passing Lamps]
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