I like playing around with the PR-base hotwires, and I've used the (ROP) 3854-L with five cells, and it's only OK, not sure if it's worth it IMO.
I think that staying with
4 cells and the Pelican 3
753-H (extensively covered in
my thread here with 4x NiMH C's as well as 4x Alkaline C's & D's) may be your best budget option - this should be
approximately ~double the output of your current bulb. However, the 3854/3853 ROP's really do crush this modest configuration that I did. Unfortunately, your 3D host is kind of in a difficult range length-wise,
too long for the 6xAA NiMH ROP's & the 26500/26650 2xLiIon ROP's, and
too short for the 6xC ROP's.
The 5-cell region is pretty thin for good bulbs, it seems to me. :candle:
Edit, copied from my thread:
Stock Mag 4D (Krypton) bulb_______ Pelican 3753-H (with the same cells)
The neat part is that you can still use the stock reflector & lens, and it even runs on the very extreme end of what the lowly alkaline cell chemistry can provide.