Hey, TK and everyone else! I am new to the world of enthusiast flashlights and to this forum, and my research on a flashlight that would be pocketable, versatile, and fun lead here after a month or so. I am excited about this flashlight, and I have been enjoying skimming this thread (I’m only up to page 30 so far). I have loved flashlights since I was a child, but never bothered to do much about it until now.
The reason I am posting is that I have a safety question about the flashlight for anyone who is educated in this: what happens if a standard, low-discharge cell (4.4A, for example) from a laptop is used in this flashlight? Would the flashlight over-stress the cell and possibly cause it to fail, overheat, or explode? Or would it merely limit the ramping and turbo based on the cell’s limits? Would the max ramp and turbo merely be limited to around 700-800 lumins? If so, by what mechanism is this achieved? I have read that vapes can cause low-discharge cells to burst due to trying to pull more amps than the cells can safely deliver. That is why I am concerned about the flashlight.
The cells I intend to use are Samsung ICR18650-22F from an aftermarket laptop battery. They are unprotected and have a max discharge of 4.4A from what I have read.
I do not care about ultra-brightness right now (I may later, just to show off). I just want a fun and functional flashlight for tasks that will rarely require more than a few hundred lumins. I do, however, want to find a use for the nine 18650 cells I harvested that still hold 88% of their capacity. That was actually what motivated me to start shopping for a new flashlight. I have an old single-AA Fenix LD12 that mostly serves my needs, but I would like a brighter flashlight. On a partly depleted alkaline cell (I know I’m supposed to use NiMH) it can only achieve 27 lumins (mode 2 of 4, 4 being 115 lumins). These cells gave me the motivation to finally get a better flashlight, and one based on a Li-Ion cell.
I would assume that the Fenix fails to achieve its max brightness due to the low voltage of a partly depleted AA cell. All modes the cell cannot power simply output the same brightness. So eventually the upper three modes are equal to the first mode in output. There must be something in the circuitry that causes the flashlight to output a brightness equal to the previous mode rather than a partial step up. I do not know enough about Li-Ion technology or electrical engineering to know if what is happening in the Fenix and its alkaline cell would also happen with a hot rod flashlight and an 18650 cell, especially since the limitation here is not primarily voltage, but amperage. And alkaline cells are not known to burst when stressed. Li-Ion cells are. EDIT: I just went for a walk and found that the Fenix actually does do partial step ups. I never noticed that before. I put a fresh cell in and the step from 2 to 3 is much greater than with the depleted cell.
By the way, I’m planning to get the Nichia 219C 5000K 83CRI emitter. I want to experience this high CRI, neutral white the enthusiasts rave about, and avoid the green tint that reportedly plagues the SST20. I would try the 4000K 219C if it were available. But maybe that would seem too warm for daytime use. I will be using this flashlight for all purposes, night and day.