I have a light that uses a CR123A battery. I did some quick measurements and found it pulls ~1.0A @ 3.7V. At 2.8V it’s more like ~1.4A. Current draw is somewhere between .9A and 1.7A depending on the input voltage. Above 3.8V current is.9A. Current consumption rises as the voltage drops with 1.7A being pulled somewhere in the 2.4-2.5V range. Below ~2.4V the current falls some. The light doesn’t have any sort of low voltage cutoff that I could determine.
So, I think a protected cell is necessary. An 18350 definitely will not fit. I’m not even sure if it can accomodate the extra length of some of the slightly longer protected RCR123A cells. As far as I understand from looking at discharge curves CR123A batteries don’t delivery anything like their rated 1.4-1.6Ah capacity under that sort of load profile. Even the best CR123A (Panasonic AFAIK) is going to be sub 1.0Ahr at usable output voltages and will probably start losing output in the 30-40 minute range.
From HKJ’s reviews it looks like the Nitecore NL166 RCR123A is probably my best bet. It’s basically the highest capacity rechargeable cell I could find in his reviews for the load I’m looking at that is protected and still CR123A sized. It looks like it will also have full output for 30-40 minutes.
Is there a better CR123A sized protected cell on the market I should be looking at instead?