ok. thanks for the info. I was hoping to avoid using protected cells and just use my reclaimed 18650 batteries, which I can still do, but need to keep an eye on output so I know about what the brightness level is when the batteries get down to about 3v. I guess I have some shopping to do.
What I have: 2d mag body
custom made sleeve to hold 2 18650 batteries(unprotected, non button top
would like to run a setup like the malkoff drop-in for 3-6 cell mags, but...
I would like to build in voltage protection(so as not to kill my unprotected cells),
and be able to put an extension...