Best Battery Choice for T Binned LuxV?


Newly Enlightened
Apr 20, 2005
Bay Area, CA
Hi all,

I am attempting my first mod, a Space Needle type light using an OAD O-sink, a borofloat lens and a T binned LuxV. I also purchased a FatMan regulator board and plan on driving the LuxV at 1A.

The only thing I need to do now is figure out what D cell mag body and batteries to use.

If I understand Georges80, the FatMan will regulate as long as the Vin does not exceed the Vf of the LuxV. Correct? So as long as I don't exceed ~6.5V the FatMan will work as intended, anything over that will be direct drive. Am I then free to choose the highest mAh I can find as long as I don't exceed a Vf of 6.5?

I was thinking about either 4 NiMH D cells in a 4D Mag body, or 4 NiMH C cells in a 3D body. Is there a better choice that I am missing? Should I buy a different regulator to use in this mod?

Thanks in advance, comments and suggestions are greatly appreciated!


Jan 10, 2005
Texas, USA, Earth
This link (which you might have seen) has the voltages for each bin:
Bin Codes Explained

This other link has lots of good info. Note the first column on the left which shows the unloaded voltage - that should give you an idea of several possible configurations: Direct Drive Chart ...

Good luck /ubbthreads/images/graemlins/smile.gif



Flashlight Enthusiast
Jul 22, 2003
I built my Lux V Mag mod using a 4 D body light with a boost converter. It works nicely, but it's really long. I find myself not using it as much as I would if it were smaller/shorter and more manageable.

If/when I do it again, I'm going to consider one of two other options. I want to stay with regulation, so my first choice might be going with some 3 or 4 AA to D adapters in a 2 D body with a buck converter. My other choice could be just sleeving a 3 C body for 123s and using a buck converter. At this point, I'm leaning toward using the 3 C body and sleeving it because battery changes would be easier in the field.

Using is a boost converter is not the only way to go with a Lux V.