That makes me go 2 places up in one day! Almost in the 555 range, thanks!
I’m just waiting to see the updated “core list”.
This is going to be a great light!!! Can’t wait to get it. Pacing…lol edit: is a great light!
If you don’t like the driver you can change it later for something better…
The_driver, that driver you linked looks very capable, does it have modes?
Yes you can see it needs improvements for longer regulated modes. At 2A already of is pretty nice.
I don’t think a long time on 2A is to be compared to 25K lumens lights stepping down to 1200lumens after a minute though 
The GT is not a hotrod going for max lumens in burst. The turbo of 2,5A gives max throw at the cost of losing regulation earlier (still we expect it to be longer after voltage losses are smaller and maybe a better bin led with little lower vf) but it has tons of throw on 2A with longer regulation.
Anyhow, will update the list later of course
Where did you hear there is no regulation? It has a nice buck driver that regulates great. The only issue is voltage sag in the springs is causing it to drop out of regulation earlier then planned.
If you bypass the springs it will fix the problem and it will regulate down to around ~15V. Lower modes will regulate much longer.
It should still be able to regulate for around 40mins+ in the final version.
I am sure Lumintop will do something about the carriers. It is just too early to be put off by rather high voltage losses the prototypes have shown.
Argh this is not the GT thread, but given your strong sentiment I’ll treat this as if you had posted it there
The difference is the same; each mode should do without crazy difficulty what it is claimed to do. I’ve already purchased the Brontelight BT31 instead.
I actually couldn’t find that thread. Sorry.
Why create such drama about simply changing your mind? Why try to trash an excellent light? Just so that you don’t feel guilty for dropping out? Just simply drop out. Others will buy the light you didn’t want. No hard feelings needed.
The BT31 I avoided after considering it. No meaningful reviews, high cost, mediocre specs for what it is, only 1 BLFer posted they actually bought it, etc. Not sure why anyone would buy it over a TN42, but neither light is in the same class as the GT, not even close.
What’s the point in a 2.5 Amperes Turbo mode when high is already 2 Amperes ?
The 25% increase from 2.0 to 2.5 Amperes will be visible on a lux meter, but hardly / not to the naked eye.
Which is why the ramp ends at 2A but turbo will be available at 2.5 for those that want it.
This is a run time chart with the BLF GT proto Narsil running two amps at the end of ramping.
This particular GT also has spring bypasses on the battery carrier.
The runs were stopped when the low voltage kicked in for the first time.
This chart is a comparison running the BLF GT on high, the original Narsil at 2.5 amps and the proto Narsil at 2 amps. Both runs were with 30Q batteries.
Nice graphs, looks regulated to me for 40 minutes, so with the 8x carrier double that.
It is not clear to me what the difference is between ‘original Narsil’ and ‘proto Narsil’. Narsil is the user interface so are they different user interfaces?
The main difference was the original Narsil ramped to the maximum current output of the driver which was 2.5 amps at the LED. Prot Narsil used here ramps to 2 amps which is where this run time test was carried out. Double click takes you to 2.5 amps.
The surprise to me was the little difference there was running at 2.5 amps against 2 amps in light output and throw.
Pretty neat, 30Qs do not have the highest mAh and it is with four where eight can be used too in the production lights.
I can’t see the runtime graph in the sole BT31 review but the text say it keeps the output above 50% indicating a decreasing output over time.
I want a keychain ring!