but with active dimming (ADT) is totally useful, is barely warm (unless you completely horizontal) and does not always after before (top. and you always have an optimal brightness.
I invite my battery about 1x a week since I often use, and there are usually still at the 3.8 to 4V battery voltage so nearly full
I can not say much because I only have this if times a battery is really empty via the supplied CR123 batteries. Amazingly, the lamp with CR123 but also very warm, although the Sens CR so much weaker light. To me it would seem, with 16340 battery, the lamp is more efficient than with CR123.
And by the way, most claiming 16340 batteries are approved by NiteCore out in this lamp - In the supplied documentation is in CR123 a check mark, and at 16340 / CR123R an X in the table. So no batteries may be used, but the LED hälts and makes with 4.2V batteries even a full-blown professional lamp ala Led Lenser M7RX competition which is much bulkier.
My Sens is already nearly 1 year old and still doing well his service on a key chain. MMN There is no better keychain lamp as this. If you do, please let me know :)
The only downside is the rotary switch, I do not like as many batteries of different sizes (especially how much of the positive pole is marked) and I have had to prepare a few batteries with insulating tape, as the lamp otherwise automatically turns on, but runs anyway and I am extremely satisfied I had found the lamp before, I could have done without a 160 Led Lenser.
