Both unprotected and protected cells work fine but they do need to be button top. Donāt know where you read protection was required, itās not in the paperwork.
Says in the paperwork that turbo will turn off after 3 minutes but left mine on for over 20 minutes and it stayed on turbo with no stepdown. Also says when temp reaches 55C it will step down, 20 minutes and no stepdown. The temp got warm but not too hot to hold, could not even feel the heat on my bare head through the headband.
I have a Spark ST6 460NW that was XM-L. I was easy to upgrade it to XM-L2 with an emitter swap. I noticed you have the XP-G version of the Spark. I guess the driver couldnāt handle an upgrade to XM-L2? However I got a bunch of XP-G lights from DX and FT and just for the heck of it left the 1.6A drivers in them and put XM-L2 into them. They draw 2amps at 4.2v now, and after about a month they still have not fried up. Your Spark might do the same if you ugraded to XM-L2, but the problem it may not be an easy fix if the XP-G driver does not stand up:
Yeah, the Spark and Zebralight were just recently purchased on closeout, both around $42-$45 shipped. I donāt use headlamps very often and not into paying big bucks for one. From reading some of your posts you use them a lot and can justify the latest leds.
Ironically due to the reflection problem, Iām trying hard to move the brunt of the lights to my hip belt. Itās just a lot harder to get things pointed in the right direction from there, but then again thatās something my spouse has been saying for years.
I ordered a neutral white armytek wizard pro today as well as the nitecore h50. I am curious as to how easily Iāll be able to pull the nitecore apart to slap a neutral XM-L2 in? Does anyone have any thoughts on this yet?
Doesnāt look easy, not much bezel sticking out and it has the red leds on each side so not much clearance for pliers.
Bummer! Ah well, still looks like a great headlamp, especially for the price!
Anyone know if the Keeppower 3400s fit ok in this headlamp?
They fit.
Great! thx.
Wasn't surprised when flat-top cells didn't work in my headlamp with Nitecore's passive polarity protection thing.
Nevertheless, I've had it for a few days and used it extensively and find that it's not too heavy at all.
This may be supplemented by a good head band and soft mount, but never once did I feel like there was a significant mass on my head while chasing crabs or going for a midnight run.
Using a NCR18650A protected, I got 1hr 40mins on highest high (claimed 565lm) which is significantly longer than I expected.
Full review coming soon.
Great news! Looking forward to a review!
Out of regulation...Honestly, I don't see it. Call it ignorance, but it seems as bright running of a battery that has burnt an hour, and a fresh one.
The button isn't stiff. Grow some muscles.
The UI. Yeah, I have to agree that it isn't the most intuitive part of the light. But come on, it really isn't that bad. 30 seconds of glancing over the manual and 5 minutes of play time and it becomes like second nature.
The glowie tail switch makes it all worth it. 
+1, really overclocker, LOL.
I took advantage of this great deal and bought three. Before you judge me, I only did this after I found out that my long lost brothers, cousins, sister was a Nigerian Prince who just died. Just send off my Western Union, now waiting on my good long lost family member to tell me where to pick up my check.
I followed your link, and got sidetracked and ended up looking at some anit slip mats, the ones that FT sells for $1.10, for $8.50 :
I bought a bunch from FT, and I can assure you that these items would not stick as in the picture.
I just glued a strong circular magnet to the tail cap end so that I can work with my beloved headlamp in my workshop
I like the way it looks!
