why isnt turbo mode working

can anyone help me solve this problem up untill recently my tk 15 has been fine using cr123a batteries i bought a spark light a nitecore intellicharger and two 18650 batteries they are eagletac 3100mah here is my problem i intended on using the 18650s in both lights my spark sl6-800cw works great in every mode and i couldnt be happier but when using the same battery in my fenix tk15 it cycles through low med and high but turbo does not work what can be the cause is it my tk 15 or is the battery to powerfull

i cant believe nobody has a answer for me

Your post is hard to read.

Your light is probably be borked. There is no reason why it shouldn't have turbo mode when using 1x18650. In fact, according to selfbuilt's tests, TK15 should be slightly brighter on turbo when running on 1x18650 compared to 2xCR123A.

Clean all the contact points and fully charge the battery. It should be about 4.2 fresh off the charger. I like AW, Redilast, and Callie's Kustom batteries. They work for me.

what do you mean borked the light works fine with cr123primaries so how can it be the contacts

Always start by cleaning the contacts and threads (inside and outside); It fixes 99% of problems.


Turbo works on primaries, it sounds like your batteries are new and the Eagletac batteries are supposedly very decent (never tried them myself), so next suspect in the list is the contacts that close the circuit.

Short explanation:
2X CR123 batteries = 6V
1X18650 battery = 3.7V.
To get the same power out of the 18650, your light need to pull more amps, which might not come through if the contacts are not clean enough.

Use punctuation. We're already helping you out of the goodness of our hearts; don't make us have to decipher your posts too.

I see three possibilities:

1) Turbo mode requires higher voltage than a single battery can provide;
2) You have to do something mechanical to activate Turbo mode, like tightening the head, and you're forgetting to do that;
3) The light is broken.

Those are my guesses, in descending order of probability.

once you've been done cleaning contacts clean with a dry cloth or dish scrubber the contacts on your new eighteen six fifty cells also make them shine then if you have a dmm stands for digital multi meter check the open circuit voltage of your new eighteen six fifty cells if they are under 4.1v put them back on the charger you got and charge them up all the way then if you still have a problem after that but not before that check back and tell us and maybe you can get more help and we can help you use some punctuation and have less of a hard to read stream of thought block of text that people find hard to understand ok

-Clean your light contacts, threads and the cell contacts-double check polarity since it is a new cell

-Check the open voltage of the new 18650 cells and fully charge

Did either of these thing work for you?
I understand why you'd want 18650 to work Primaries get expensive:wave:

fyrstormer said:

[...]
1) Turbo mode requires higher voltage than a single battery can provide;
2) You have to do something mechanical to activate Turbo mode, like tightening the head, and you're forgetting to do that;
3) The light is broken.

[...]

Click to expand...

Sorry to correct you man, but :
1) no, the TK15 was designed to work with 1X18650 or 2X CR123.
2) mode button for low, med, high, turbo in sequence; can't miss the turbo unless you blink very slowly.
3) could be, but I would be very surprised as it works on primaries.

I see 90% of dirty contacts, bad or weak battery and a slight possibility of driver defectiveness. Let me know if I'm wrong.