Originally Posted by
VegasTriker
I have two such lights, a one and five CREE XML-T6 bike headlights and a couple of battery packs. Neither light comes apart easily. The battery packs I own are exactly the right size to be made from four and six 18650 cells and there is no extra room for electronics. My bet is that the controller circuit is behind the LED module in the lamp head. Frankly I never use either light as I quickly became disillusioned by the battery pack and cord being a PIA to deal with. You might take your question to BudgetLightForums.com. There is a group of dedicated light modders there
Flashlight Modding and DIY Parts | BudgetLightForum.com who would surely know the answer to your question. I generally use a CREE XML-T6 flashlight for my front light. Flashlight and secure flashlight holder (w/o 18650 battery) were well under $10. No cords, easy on and off, very secure, and plenty bright.
Thanks. I think you're right that the controller circuit is in the light.
I agree that these lights are something of a PIA. I usually use a Serfas True 500+ on my handlebars (very easy on/off) and a single-18650 cell flashlight on my helmet. I have the clone light partly for backup purposes and partly for when I want longer run time before changing the batteries. Also, I can bring my bike into a secure area of my building at work, so I can just leave the light and battery pack on the bike during the day. These clone lights aren't great in some ways, but I think they're useful enough to keep one around.