All protected batteries are like that or will be destroyed in case of over discharge.
If you don't want to be in dark, simply get extra set of batteries or get a 26650 flashlight which has much longer run time per charge.
Capacity of each 26650 is 5500mAh compare to capacity of 550mAh rechargeable 123
I'm not in need of a new solution; the OP is.
I have no issues with the LFPs I'm using, but wanted the OP to be aware of this 'feature'.
My K2s are not protected, but because they're LFP, I can make an exception; tradeoffs, as always. They can also be safely, routinely discharged to a lower voltage than some other chemistries (2.5V being no big deal at all), and that, along with a final discharge curve which does not terminate in a vertical line, makes them quite usable for me in practice.
Other protected cells do indeed shut off suddenly when their overdischarge protection kicks in (and are generally all I use when appropriate / possible); however the primary point here is that their voltage decreases as they discharge, and
depending on the light, that often provides me with
some advance warning of the impending event. Those lights may also provide their own advance warning as well (which does not mean shutting off abruptly). In my case,
some warning is far, far better than zero.
Sudden, total darkness can put my safety at risk in my line of work ('heavy' industrial environment, with safety risks being routine). Backup cells / lights are of no value after I'm already been put in a bad situation (like injured or killed). I don't know how you use your lights, but I believe the OP is a LEO, and their needs may be more in line with my own, so my perspective may be applicable to them.
I don't just recommend based solely on my own needs, but when possible, try to consider the needs of the OP.
The lower capacity is indeed a tradeoff, but works fine in my application. No issue. I can plan around that known.
These things shouldn't be over-simplified, and there are several factors in play, and they must be considered in their totality. Engineering is
always about prioritized tradeoffs, not just isolated facts. My post was for the benefit of the OP. I realize you've already determined the optimal solutions for your personal apps. The OP likely has not.
Hope that clarifies my points for you,
and more importantly, the OP.