I'm trying to think through this process, but can't seem to come up with any benefit to running additional cells in a 9p light. Obviously, the 9p was designed for more cells to create more voltage to run incan lamps, but with LED technology not needing the voltage, but current flow instead, I am re-thinking my battery setup.
Is there really any benefit to the longer body of the 9p for more cells? Are 2 18500's (or 17500's) really better than a single 18650 and a spacer? Is there really a good use for the extra length battery wise?
I'm currently running an M61SHO in my 9p with standard 123's because the SHO needs the higher voltage (>6vDC). But even the SHO, while a mighty fine light, only puts out 450 lumens. I'm thinking I could get 650-700 with a Nailbender using the CreeXML's, but they don't take near the voltage to run as what the 9p body was designed for. So I could run the same head just as easy in a 6p with the same amount of light for the same length of time using say 1x18650 @ 3100mAH.
Obviously, I understand that the more voltage you have, the less current you need to make the same power - that's basic high school physics, but that doesn't necessarily equate to longer run-times with LED's. Or maybe I have more learning...
So, I guess my question is, can someone help me with figuring out the benefit of the longer 9p body with modern LED's? I guess I'm old fashioned and I'd hate for the extra battery space to be wasted when I could accomplish the same thing with a shorter torch.