Fireflies E07 preview

Why I asked you, my research C8F (18650) at an air temperature of 24C grieved me:

- in 990Lm mode. After 20 minutes, the head temperature reached 58 degrees.

  • in 650Lm mode. After 25 minutes, the head temperature reached 54 degrees.
    I think the design lacks cooling fins and more. In version 21700, added cooling fins, but I think need more.
    It was interesting to compare with other studies. And I wonder how the Fireflies E07 will show

TBH, I’d be just as happy with this using 3 emitters, 4, 5, 6, or 7. As long as it has decent performance at ~1000 lm and below, the brighter modes are mostly just a bonus. I’d rather have less weight instead of more turbo.

If it ships with Anduril, it’ll have a relatively sane ceiling by default, which should help a lot with not overheating. But turbo is still there for quick bursts.

Clip pushed onto body is a big NO.
Solarforce style is much better.
Mike

sp5it, that’s a good point. I also prefer a captive clip which cannot slip off the light. However, I have found the Olight S-Mini clip works pretty well, despite being a clip-on clip.

What I’d ideally look for is a deep-carry clip which extends almost to the end of the light. This shape works really well:

But on this light, instead of having two arms which clip on, it’d probably be best to make the clip thread in. And it’d be bezel-down, of course.

The Oveready universal clip shows the captive design nicely. I would mostly just modify it for deep carry:

… but not too deep. :smiley:

Slip off and scratches when put-remove clip a few times.
Mike

Unfortunately, added mass doesn’t allow it to shed heat faster. It is useful for maintaining high “steady” output longer. For example, I have eight Convoy S2+ hosts (6 aluminum and 2 copper) that I’ve been using/experimenting with them by tail standing as room lighting on nightly basis for several months a while ago. Using the same pill at the same output mode in a much heavier copper Convoy S2+ host vs the standard aluminum versions, the copper host takes about 3 times as long (seat of the pants estimate… not going to spend time to swap out the pills to stop watch it) to raise to unbearable temperatures and also takes much longer to cool down. So adding mass doesn’t really increase the max sustained output running indefinitely, but being able to use the same mode for 30 minutes instead of 10 minutes to me greatly increases the practicality of the light.

To control the temp under low-mid output modes running indefinitely, we need more surface area to radiate heat, and also air movement to convect heat away. Still indoor air won’t do much good. However, adding a couple of fins won’t do much to extend turbo runtimes because the heat gain is so much faster than heat loss through radiation and convection.

Also the Sofirn C8F driver was designed for high output and I suspect is not very efficient. With an efficient driver, I think the host can likely maintain 1,000 lumens comfortably for 30+ minutes. Even the 90CRI T050R emitters, with less surface area than the C8F and weigh only 126g can maintain 820 lumens in room temp without active cooling as tested by Maukka. However, the TO50R has far higher efficacy than most flashlights. Maukka tested the TO50R at 125 lm/w at 250 lm compared to the ROT66 at 79 lm/w at 100 lm.

Where did you pull these numbers from? To me these are completely baseless and is misleading for those unaware. I suspect turbo is designed to last 30s on the E07 as is. By adding 40g to the head as I suggested, it will last much longer. Adding 40g to the head of the E07 is almost doubling the mass and should be close to 100+ g and will allow turbo runtime to increase much more than 3 sec while brightness decreases much slower.

I just tested my C8F again and at 2 minutes, it only dropped to 2,680 lumens but for some reason abruptly dropped from 2,670 lumens to 70 lumens at 2.5 minutes (timed step down or defect?). However, the head was still comfortably warm at 2.5 min.

Because E07 has 7 emitters, the current will be spread among the emitter so each emitter would be pushed less than a 4 or 3 emitter light under the same setup. However, this doesn’t change the fact that a 30T battery is capable of pumping much more power (watts) than a 30Q in a C8F.

I understand some people like yourself do not need the light to be practical and do not care about having stable output for longer periods. I also understand some never use their lights over a couple hundred lumens but there are much smaller lights for that. However, there are also some people who prefer a Turbo that last much longer than the 20sec on the D4. I actually use my lights for work purposes illuminating large interior spaces and I see this light to have the potential to replace my TC20, which can maintain about 1,000-1,200 lumens and is the current best for its size. I also own 3 D4 and only use them as toy lights because I can’t find any practical application for them.

FF already have a 4 LED light, which is the PL47, which is basically a D4 headlamp, that I already have two on order. I don’t see a point for FF to make another quad given there’s already the D4, D4S, EC65, TO46R, and TO50R that fulfills all needs from hotrod toy to practical light.

A few examples of fins done right to increase the surface area :
Eagle Eye X6 // Skilhunt H03 // 4Sevens maelstrom X7 // Sunwayman V10R (secure and removable deep-pocket-carry-clip done right)

No need to make a bigger head when the surface area of thermal exchange is already bigger with fins done properly.

My favorite is the TR-J20. The massive finned head on this thing can probably handle 10k+ lumens continuous if using an efficient driver and leds.

I also love the massive fins on the Olight SR90. Hoping they release an updated version with modern LEDs and drivers.

Did you configure the Emisar’s for max temperature?

I agree with SKV89 that increasing the head mass will improve the turbo runtime, and it’s really useful. I don’t know how much it’ll improve but comparing my D4 and D4S, both set to max temp, the difference is indeed big. Further, for me it won’t make a difference in EDC so better safe than sorry.

E07 look well but for me 25 degree is not option. I have no where to use. it would be nice to have a spare option of 15 degree.
also samsung leds!

By milling deep fins, the thermal transfer by convection is increased while the mass is reduced. :wink:

I never configured the temp but it gets burning hot. Max temp is probably set higher than on my D4s.

I would sacrifice some mass for additional fins. Although I would love to see 1+ min turbo, having higher sustained low-mid power level is more useful for me than extending turbo runtime. However, they can easily add back the mass by thickening the shelf and walls.

YES! The trj20 thing. Thats what i was thinking. In copper.

Hi guys. I want to buy batteries in advance.
What do you advise?

Shockli 21700 4550mAh, Samsung INR 21700-40T (preferably)

I don’t know where did you get the 30s from. Myself I did a quick calculation based on assumption that turbo time is directly proportional to mass and inversely proportional to number of emitters. As I noted this method has flaws but should arrive in the ballpark of being correct.

You’re very wrong. I care about regulation and I care a lot about practicality. But I can live without the former and the latter is precisely the reason why I don’t like adding mass for mere improvement to turbo time.

My use case is to have just a couple of hundred lumens sustained. But I blast turbo to either get a better view of some area or to see farther. Usually 10 seconds is enough. Sometimes it’s not. But those cases are definitely not worth a weight increase.

“Maintain” means efficiency and heat shedding capabilities. Not weight. And 1200 lm is not turbo, it’s just a medium mode.
7 emitters give good efficiency, though with a different driver that could be better. On the head-shedding side the head is barely finned and quite small.
Effectively, I don’t see this light as a sustenance queen. I’m far from being certain about that though.

11.11 might be a good time to buy batteries.
Depends on the needs

  • Samsung INR 21700-30T - for max output
  • Liitokala Lii-40A - good cell for a good price
  • Samsung INR 21700-40T - very good cell, a bit better than Lii-40A
  • Shockli 21700 4550mAh - very good cell, not very expensive
  • Sanyo NCR21700A - very good high-capacity cell, though I would hesitate to use it frequently with a hot-rod like that

Myself, I have Lii-40A already (and no light to use them in :wink: ). If I didn’t have them, my pick would be Shockli 21700 4550mAh for runtime and 30T for output.

I like to add that the Sofirn 21700 4.000mAh seems to be quite comparable to the Samsung 40T at a very decent price. Maybe it will be even cheaper on the 11/11 sale. For maximum runtime I recommend the Samsung 50E cell with 5.000mAh.