What is the input voltage range of a stock TK70?
Stock TK70 takes 3-4D size batteries. Alkaleaks or Nimh
Working Voltage: 4.8V - 8.0V
Max Input Current: 6.5A - 7A
From a quick google.
I think my input current was less than 3A with the 3 lithiums. I can check later to verify. Dont hold me to that number just yet.
Ken
Thanks for your link.
The Thai TK70S version uses either 2 li-ion or the usual 4 nimh
All TK70 can use 2 Li-ion cells. Not sure about 3 though.
Two of either links will be good enough?
http://www.fasttech.com/products/1420/10002171/1156400-feilong-32600-37v-5000mah-rechargeable-li-ion-batt
(as long as the D cell)
Yup!
Have you tried this set-up or something similar? Aside from the weight savings, what are the other things that can be gained with such set-up?
Shorter and better balance with a dummy cell near the head. I would prefer a 2D tube but cant find one.
I just measured tailcap current with 3 fresh 26650s. It was 3.84A on high. It stayed at 3.84A for 30 seconds of run time. I suppose my driver is safe!
Ken
wow nice mod! can you tell me how many lumens now?
I can only really go by Matches test on the XML2 led on copper test. At 5100ma I would be at 4800 lumen. I like this light a lot because the reflectors are deep and it really throws well! I believe there is not a true way to convert lux to lumen?
Ken
So you have the stock driver in and running at 12.6V?
And its not smoking?
Thats correct! I even tried 4 cells. It didnt like it. The light would only shine dimly. This driver is very robust!
The only mod I did to the driver was bridge the sense resistors. Thats it!
I have about an hour run time on it with this mod too.
Ken
The math doesn’t add up.
Input power is around 46 watts.
Output power at 5.75 amps per emitter == 5.75amp x 3.8(vf at 5.75A) x 3(emitters) = 65 watts.
I didnt think to do the math. I am just measuring current in real time. I could have a fualty multimeter. Or maybe I’m not using heavy enough wire on my meter to test?
The 5.75A was a bench test with a Pb 12 volt battery. The assembled test was 5.1A at the emitters. The current test to the emitters was done at a different time when I did the tailcap current test. I do have another meter. I can try and test the output to the emitters and the tailcap at the same time. What efficiency are you using for the driver?
Ken
I just did another tail cap current read. I used 10 gauge tin coated copper wire as short as I could I got a tail cap reading of 4.54A. That should be correct. I should be a little more thorough in my tests. I just get so excited to see such a gain in performance and I love to share my results. Thank you for allowing me correct my accuracy.
Ken
Am I getting it wrongly? TK70 stock driver can take 3 x 32650? Wow!
Thats right! BUT, I dont know for how long. I am uncertain if it will last nor am I certian how hard I am pushing the components on the driver itself.
Mod at your own risk! I am comfortable with it, but I do not leave my highly modded lights on for extended periods of time either. If this TK70 crashed I would not be upset because I took it in my own hands to believe information gathered to be true from the net. Everyone has been great to me on this board. The last thing I want to do is share false information and be “that guy” who told me it would work and it didn’t.
Okay I’m done. Hahahaha! Its dark out! Lets make it light agian!
Ken