charging technique for a dive light?

Planning to build a PVC dive light based on either a h6flex or b3flex, depending on whether I use a SSt-90 or the SST-50. Quick mathematics tells me a triple-column of 18650's should fit the inside diameter of 1 1/2" PVC pipe. I'm thinking two or three in series, i.e. 3p/2S or 3p/3S (correct?). The same triple column of 26650's should fit into 2 1/2" PVC.

anyway,

I was planning to integrate a protection PCB for overvoltage and low voltage protection until I realized the Techflex manual states the LED driver has a user programmable low voltage cutout.

Do I still need to use a protection PCB just for charging purposes or is the apparent redundancy not really so and I should just purchase and integrate the board?

I'll start tracking down a reflector and lense later. Has anyone employed a hydraulic sight glass using a NPT before? I would think that 1 1/2" PVC pipe with a matching lense mounted via a pipe thread would be slick. keyword: fused sight glass.

If this posting makes it to the board this time I'll post a link to the above fitting description.

Thanks

You have two threads that are very similar. I'm closing this one. You can expand on the other one to include questions in this thread.

Bill