Rechargeable batteries for Fenix TK11

[actuary32174]

I am new to this group and was hoping I could get a little help. I am thinking of purchasing a Fenix TK11. The questions that I have are about the 18650 batteries that go into it:

1. What are the performance differences, if any, between the rechargeable and nonrechargeable 18650 batteries for the TK11?

2. Depending upon the answer for question1, what brand of 18650 would perform the longest and the best. Also, could a site for purchase be recommended?

I anticipate using the TK11 just once and a while for most probably short periods of time.

Thanks for the help,
Rick

 

[DM51]

Welcome to CPF, actuary32174.

I'm moving your thread to the LED Flashlight section, where there are several discussions about the TK11.

 

[unique]

AW's Def the best batteries for rechargeable: http://www.cpfmarketplace.com/mp/showthread.php?t=187951

 

[rockz4532]

if you are not going to use it that much, i suggest primaries.

 

[I came to the light...]

AW is pretty much the CPF standard - you can be sure of getting just what you expect. But I suggest buying trustfire grey-label 18650s from DX. They have also been tested thoroughly, and have more capacity than AWs. But be warned: shipping from DX is very slow.

 

[dezertdog]

I got mine from LightHound, SUPER fast shipping, they are located in TX.

http://www.lighthound.com/AW-18650-Protected-2200-mAh-Rechargeable-Lithium-Battery_p_20-105.html


I am confused by the TK11, maybe someone can clear this up. On their site they claim that it requires a 4.2V 18650. I understood that the LED circuits were either designed for two cells OR a single cell, but NOT both (for example the Malkoff M30 vs the M60).

Does the TK11 only run in regulation for a short period of time (when the battery is above 3.8 volts) on the single cell 18650 and then go to direct drive once it hits 3.7 volts? This doesn't sound ideal.

I see that the site says it has "two digitally regulated modes", but how is this possible when switching between single and double cell use? It would seem that there would need to be 4 modes, two for each voltage level.

 

[dezertdog]

AW is pretty much the CPF standard - you can be sure of getting just what you expect. But I suggest buying trustfire grey-label 18650s from DX. They have also been tested thoroughly, and have more capacity than AWs. But be warned: shipping from DX is very slow.

Regarding those trustfire's, I'm skepticle about that 2400mAh rating. I've used the side x side with the AWs and they seem to underperform in each case.

 

[DM51]

A post from StriderSMF has been split off from here to form a new thread in the Batteries section.

 

[Toaster]

I am confused by the TK11, maybe someone can clear this up. On their site they claim that it requires a 4.2V 18650. I understood that the LED circuits were either designed for two cells OR a single cell, but NOT both (for example the Malkoff M30 vs the M60).

Does the TK11 only run in regulation for a short period of time (when the battery is above 3.8 volts) on the single cell 18650 and then go to direct drive once it hits 3.7 volts? This doesn't sound ideal.

I see that the site says it has "two digitally regulated modes", but how is this possible when switching between single and double cell use? It would seem that there would need to be 4 modes, two for each voltage level.

TK11 contains a buck circuit. Running on 18650 high mode will be direct drive with declining output over time. Low mode is flat regulated regardless of battery choice. This is typical behavior for currently available 18650/2xCR123 powered lights. If you want flat regulation on 18650 your only choice at this time is to get an 18650 only light. However given your intended sporadic use I would skip the idea altogether and just get some CR123 primaries.

 

[Mjolnir]

I have a few of the blue trustfire 18650 batteries (I am pretty sure they are almost the same as the grey ones, except they claim to be 2500 Mah instead of 2400 Mah, and they seem to not have short circuit protection). In my Eagletac T10L I got almost exactly 2 hours of battery life (the advertised value), while Light-reviews.com got 1 hour and 50 minutes with AW 2200 Mah cells. I realize this is not at all a precise measurement, but it seems that the trustfire ones (the blue ones at least) have at least comparable capacity to the AW ones, if not more. However, it seems to be sheer luck that determines if you get good batteries or not.