I think the light output is being severely limited by the springs. They are probably phosphor bronze/BeCu short springs can carry quite a bit of current, especially if it’s really stiff, meaning it has very low contact resistance initially.
The problem however is that it takes into account if the light is new. Pure copper oxidizes very quickly, meaning contact resistance shoots up dramatically, and even faster with heat, which can great hot spots, and contact resistance goes up because of heat.
Using gold plated springs, or even better, dual springs, would help a ton in this regard.
You are probably right. The original springs that came with the NA40SE is very thick. The replacement is thinner with more loops, which I’m guessing is from the version 1 NA40.
My xhp70.2 (4 emitters) and FET driver with 2 x 26350 got 4100lm measured similarly. I bet using that single Shockli is way better than my 26350 cells.
This NA40 would be pretty sweet with a better UI like Tom E used. You retain the charging as well. That’s one advantage compared to building up a C8F 21700.
Did you happen to measure how many amps it’s pulling across the tail cap on turbo?
my NA40 pulls nearly 15A with fresh 26650 cell, so my wild guess is about 5000lumen
the light is also equipped with temprature control, because the turbo last much longer when using this light under water
Yes, that’s probably the reason why folks aren’t getting much comfortably above 4000 lumens, much less hitting 6000 lumens.
A single cell gunning 6000 lumens at very high amps is going to place a lot of stress and emphasis not only on the 1 x 26650, but also on the springs, the cleanliness of contact points, all the components in the power path.
You cannot use the Keeperpower 26650s, they are like mid current cells only.
The best Keeperpower 26650 vs Liitokala INR26650 @ 20A “only”. I think we need to look at 30A (see subsequent posts).
Yep. To get this power out of a single cell, it is imperative to reduce resistance as much as possible.
The biggest one here is the spring. Why aren’t they using dual BeCu springs, or at least, a coated spring? Uncoated copper alloy springs will develop oxides on the layers overtime, boosting contact resistance, and creating hot spots, and boosting the voltage loss even further.
That means even if they are using the highest conductivity BeCu C17500, performance will get worse over time.
Look at djozz’s test on the SST-40. In the best scenarios, cooling and excellent bins, it needs 6A per emitter at 2000 lumens. If you want 6000 lumens OTF as measured in all of our ceiling bounces/lumens tubes/integrating sphere, you’d need much more after factoring all the lens losses, driver losses, heat etc.
Probably need 2400 lumens in dijozz’s test if there is a 17% loss to 2000 lumens OTF, thus 9A per emitter.
I am guessing 27-30A at the tailcap is gonna be needed, a fair bit of which is really heat and not lumens. Don’t even dream about efficiency once comfortably past 6 amps per emitter.
At 0,052mOhm of resistance, wouldn’t you be trying to pull, at 3,6V average voltage, about 69 000A if there were not other resistances in the circuit, including the cell?
Yeah. Maybe you’d kill the emitters if there was a 6000mAh version of the Samsung 30T and bypasses everywhere.
Seriously just look at other “6000 lumens” lights measured in our ceiling bounce/tubes/spheres, like our ubiquitous BLF Q8 with 4 x XP-L.
Of course 4pcs of XP-L (at 1500 OTF lumens) is going to be much more efficient than 3pcs of SST-40 (at 2000 OTF lumens each). But even so, we are talking like about 25 amps for the 18650 in 4P config? Or is it closer to 30 amps?
This is a 30A light, if you wanna do 6k OTF lumens, low 20-ish if you want to gun at 5k OTF.
LOL…… We need to get the bottleneck out from the tail-end for sure.
Actually thinking about that, we use 2.5mm diameter copper wires here for our 240AC. That’s thicker than 12awg. More like 10awg.
Just thinking of a very common and convenient source. And seriously speaking, the 10awg stuff that some electricians source for is sucky……that’s why some of our local setups with air conditioner wirings doing higher currents might cause degrade and subsequently cause fires over time etc.
It might still be “practical” in the real world. A 5-20 seconds burst, then charge 2-5 minutes with a powerbank, then 5-20 seconds burst. Look at the above various batt discharge graphs plots @ high current and how it slides down as to why this is so. Even a VTC6 is doable. Such high-drain cells are able to accept relatively high currents till the very end so it’d be relatively fast top-ups.
For those flashaholic meetups thingys……you know what i mean?
And it would be especially nice for people having winter conditions.
131mm x 41mm head package. Empty weight 213g as per Taobao listing.
Lets face it, there are so many people here in BLF owning MT09R (multiples even) with TA driver and that’s also around this level in terms of current consumption.
So to be very fair to the light and maker/modder, quite “workable” and “practical”, if you can get it from TB direct, one for the collection at that price, perhaps.
Dollar per lumen is actually similar to the MT09R.
There are Samsung 20S for sale in TB, batt pulls……seemingly legit from end-user testing, 7 milli ohms. Seller tested 6 milliohms on the YR1030 tester. So the whole thingy is definitely doable from start to finish.
Don’t think this has been posted here or in other threads discussing this……
For the record. I presume that this is legit. Using the Nightwatch 4800mAh 35A store battery.
No mention of ambient temp or what, actually i believe it might be cooled in a certain way as i certainly won’t be able to get my BLF Q8 doing this, no way at all.