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. 
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 ). 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.
thank you very much for the tips.
I said I suspect they will design turbo to last 30s, which is based on the ROT66. To me the calculations you claim to have made completely don’t make any sense. I don’t see how increasing the the mass in the head by at least 50% will only increase turbo runtime by 3s. If FF really designed Turbo to last only 12.5s as you calculated, that would turn away a good number of purchases. There were plenty of comments laughing at the 10s turbo on the Nitecore TM10K. Also the D4 and PL47 already fill the short blast turbo toy category so it would be a bad business decision to have the E07 turbo last only 12.5s and with probably equally poor sustained output. E.g., the D4 drops to 250lumens at 60s and below 200lumens a bit after and subsequently oscillating around 2xx lumens the whole way (depending whether tail standing or handheld).
As I stated earlier, if I had to choose, I prefer more fins over more mass. But preferably and optimally, mass should be added as fins where possible to increase heat dissipation; but to maintain the size of the light it seems not easy to increase fins. However just adding mass alone will extend low and mid power runtimes also, not just turbo as I showed in my posts above. I would much rather the light can handle a decent output for 30 minutes than 15 minutes.
You are restating to me exactly what I already explained in my posts above.
Adding mass extends steady output runtime and slows temperature gain at all output levels. I normally use my flashlights for 20 minutes or so at a time so if a flashlight like the TC20 can maintain 1,000 lumens for 30 minutes, then I say it can maintain 1,000 lumens for my typical use cases and probably most uses cases.
Right now, the 138g of the E07 is lighter than every single other light of its size class yet it is the most powerful one. Your own post here shows a list of other lights and they are all heavier. I have never heard of anyone complaining about any of those lights are heavy. Adding 40g to the head of this light is hardly noticeable and it will still be lighter than the majority of those less powerful lights in your list. I suspect most potential customers would prefer the very noticeable performance/runtime advantages from this hardly noticeable increase in weight. I already provided information from my own testing in my posts above how much added mass can benefit maintaining steady output and reducing rate of temperature rise.
I bought 4 ROT66, 2 PL47, but I will probably buy only 1 E07 if it is only good for 12.5s turbo, and probably equally poor low-mid level thermal/output performance. However, if the E07 has at least the same output/thermal performance of the D4S and preferably the C8F and TC20, I will probably buy a couple. My friends who use flashlights for work will surely ask me to order some for them if it turns out more than just another D4 toy.
These lights are so small, why not add 80g of mass instead and make turbo run times acceptable? It's not as if this light is going to break anyone's hand holding it from being too heavy.