Originally Posted by
cyccommute
That's not been my experience. The lamps I have put out the same quality and quantity of light for the 1.5 to 2 hours I use them. That's using NiMH batteries which have a flatter discharge curve than SLA. And 4.5 Ahr batteries will last about 2.5 hours.
+1
I'm running twin 20W halogens @ 14.4V and I've never had my lights go noticeably dim on me until they are just about ready to discharge fully. They may be getting dimmer as I ride, but I can't see the difference... so I don't care. I'm using a 5Ah NiMH battery, and I get about 1.5 hours of runtime when I'm at full flamethrower mode.
The one thing that I did for my lighting system is installed a Lightbrain controller. It has more slick and useful features than you can shake a stick at... the best $38 I've spent in a long time.