It won’t increase output , but it will increase efficiency (lower resistance , so driver will deliver the same amps at the leds , and it will draw less amps than before from the batteries) .
Agree! But no output increase…maybe a gain in output at the end of the discharge.
Thanks JM, nice review and nice pics. I really really like the size and performance of this one! I have been very impressed with the TN42 and I WANT this TN40 badly! 
Difficult to decide on though, as my TM16 blows it’s doors off. Just sayin. (I modded the TM16, it’s making 6969 lumens)
Well then, with your skills I would mod the tn40s with 4x Xhp35hi so then you can blow the socks off of your tm16!
It’s possible to get 9000 lumens to the tn40s
~8.5k lumens with xhp35 hi and 500kcd and around 10k lumens with xhp35 hd for ~300kcd , for tn40s (from actual builds , i only remember leds were running near max amps) . Anyway , even with the stock xp-l hi’s , tn40s gets hot quick …
Yes, mine arrived yesterday and about 3minutes its very hot :cry:
With 4 xhp35 this will heats more?
120 Watt’s makes a lot of heat in a flashlight. It’s really just that simple. Whether or not it would push that much remains to be seen, but ideally the XHP-35 is at it’s best at 2.5A so 4 of them would be 10A, at over 12V, which obviously is just a lot of power.
I have been wanting this flashlight for over a year now. Can’t wait till HKE has the TN40S back in stock. I was very impressed with my L6 I purchased a few weeks ago. The TN should blow my eye’s out from all the reviews and videos I have been looking at. Reading the above posts on the TN40 is really assuring me that it will be money well spent! 500kcd with 4 emitters!!! That sounds amazing 
It’s like the TN42 on steroids to the 4th power! Sense I am very new to modding I think I’ll mess with my cheaper lights before blowing up a 2 bill flashlight
It surprises me
Whats the battery they use in their battery pack ?
Isnt it theirs ? Panasonic NCR18650B, not exactly high drain
I think it is NCR18650B. In terms of required current it’s sufficient. However, high drain batteries have lower voltage sag than NCR18650B. Depending on the driver design, and I think this is the case with the TN40, your output relies on the driver input voltage. So the higher the driver input voltage (= less sag), the higher the light output.
This is probably the reason that with 30Qs a higher output is measured compared to GAs; less voltage sag with 30Qs.
Make sense… so we can assume that comment is not valid with full batteries
It is a massive, powerful flashlight! Like this. But, I think TN40 light isn't for normal work. If you are doing night duty type work, then it could be helpful for you. But, as a normal user it is not an essential light. It has 4400 lumens which could be harmful for the eyes as well. As for normal rechargeable flashlight I would like to read https://totalguide.org review and select top rated flashlight.
Comparison of tn40 and tn40vn would be very interesting.
How did you mount it to a Tripod? I would like to do that on my TK75
Hello guys,
I am planning to buy either TN40S or TN42. I know that many reviewers adjust their camera shutter speed to prevent overexposure but how does TN42 look like to naked eye? Does it spill the light or is it like a laser?
Thank you.
I had both and sold TN42. You could only need it, if you want to play around. It looks like laser beam. No useful spill.
TN40s is for real world use and it has more throw than you maybe really gonna need.
Thank you. May I ask which batteries are you using for TN40S?
30Q or VTC6 is the best choice for it.
Thank you so much. Is there any better battery than these? I see they are pretty popular and kinda cheap. Around $6.
No for this application they are the best, because of good runtime and amperage.
For TN42 it would be Panasonic, Sanyo GA or something similar.