I’ve only tried two CR123-sized cells…
- Nitecore NL-166 (RCR123A) protected 650mAh
- KeepPower 900mAh ICR18350 protected button top
The Nitecores go into my JB RRT01, one at a time. It can fit 18350 batteries, but it turns out the KeepPower cells are too long to fit. It doesn’t seem to have low-voltage protection, so I stick with protected cells.
Two KeepPower cells go into my P60 (SF L2m) with UV drop-in, since it works much better at ~8v than at ~4v. They just barely fit though, due to the massive protection boards on the ends. I figured I should use protected cells since the drop-in is basically direct drive with no low-voltage detection, but… wow, these cells are huge. It took a few tries to even get them both in at the same time without crushing anything.
In any case, both seem okay for my purposes. I prefer thinner, longer cells though.