TK30 on three primaries?

Let me start by saying I have a sort of stubborn attitude regarding my flashlights. Except for only a very few exceptions, I always use primaries in my LED lights, and I always use rechargeables in my incandescent lights. Now it has been discussed before, about the TK30 seemingly non compatible on four CR123a batteries despite the included instruction manual indicating other wise. I myself self have found this to be true in with the following glitches:

-I've heard it mentioned before, the lowest mode isn't really as low as it's supposed to be.
-When using the turbo there's noticeable moment when it starts in the lower mode before stepping up to full power.

Now, my question is if this could be solved with a dummy CR123 spacer and the use of three primaries. I would also find such a configuration desireable since all my lithium batteries are titanium batteries in double and triple stacks.

Deputy T. said:

Let me start by saying I have a sort of stubborn attitude regarding my flashlights. Except for only a very few exceptions, I always use primaries in my LED lights, and I always use rechargeables in my incandescent lights. Now it has been discussed before, about the TK30 seemingly non compatible on four CR123a batteries despite the included instruction manual indicating other wise. I myself self have found this to be true in with the following glitches:

-I've heard it mentioned before, the lowest mode isn't really as low as it's supposed to be.
-When using the turbo there's noticeable moment when it starts in the lower mode before stepping up to full power.

Now, my question is if this could be solved with a dummy CR123 spacer and the use of three primaries. I would also find such a configuration desireable since all my lithium batteries are titanium batteries in double and triple stacks.

Click to expand...

Both of these issues I find in my TK30.

I don't think it would be any trouble by using 3 cells. The only thing I guess would happen is that turbomode would be somewhere between the level of the 2 and 4 cells option. But don't know how it could be solved by using 3cells. The 2 and 3-pack of the Titaniums is a very good idéa, I have them too! :twothumbs

I have a thought of using TK30 with 4AA which would be possible with an extra extension tube (don't know if it's possible to order that alone) and a thin pipe. TK30 works between 3 and 12 V, so it would be possible. The brightness with 4,8V is unsure, though.

Regards, Patric

Deputy T. said:

Now, my question is if this could be solved with a dummy CR123 spacer and the use of three primaries. I would also find such a configuration desireable since all my lithium batteries are titanium batteries in double and triple stacks.

Click to expand...

As long as the battery voltage is above 4 volt the TK30 will run at full power with very good stabilization of the light output.
In my Danish review I did a voltage/current/lux scan for both high and low modes. It will measure the battery voltage when turned on and then select high/low mode depending on it.

Swedpat said:

But don't know how it could be solved by using 3cells.

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I was thinking that full output would be possible since at load, the voltage should be in the same neighborhood as 2 lithium ion batteries.

Now four months later, I've finally gotten around to ordering more batteries and I threw in a dummy cell from battery junction while I was at it. I am quite pleased to report that my TK30 works flawlessly on 3 lithium primaries. I highly recommend it to anyone who does not wish to use Lithium Ion batteries.

Hi Deputy T,

I still am not sure I understand the advantage of using 3 cells instead of four if the length will be the same, is it mainly for using Titanium triple pack?

HKJ wrote:
"As long as the battery voltage is above 4 volt the TK30 will run at full power with very good stabilization of the light output"

This obviously isn't correct because at 6V the output is 370lumens compared to 640lm at 12V. This stated difference seems to be very correct; with my lightmeter the measured output with 2 cells is around 60% of the output with 4 cells. Did you measured the output difference between 3 and 4 cells?

Regards, Patric

Swedpat said:

HKJ wrote:
"As long as the battery voltage is above 4 volt the TK30 will run at full power with very good stabilization of the light output"

This obviously isn't correct because at 6V the output is 370lumens compared to 640lm at 12V.

Click to expand...

My statement is correct, as can be seen from the curves in my review.

What you did miss was the sentence that the light measures the voltage at startup, i.e. if the startup voltage is high enough to trigger 640 lumen, it will stay in 640 lumen down to about 4 volt.

HKJ said:

My statement is correct, as can be seen from the curves in my review.

What you did miss was the sentence that the light measures the voltage at startup, i.e. if the startup voltage is high enough to trigger 640 lumen, it will stay in 640 lumen down to about 4 volt.

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Ok, sorry, didn't know that the LED could work in that way! :thumbsup:

Swedpat said:

Ok, sorry, didn't know that the LED could work in that way! :thumbsup:

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Not the led, but the driver.

The driver has a microprocessor that measures the voltage and then select 370/640 lumen mode.

HKJ said:

Not the led, but the driver.

The driver has a microprocessor that measures the voltage and then select 370/640 lumen mode.

Click to expand...

Interesting, but do you know what the result will be with 3xCR123 and 9V, which mode will the driver then choose?
Also I earlier wondered about using TK30 with 4AA cells using another extender(may be an unpractical idea because of the length though).
If using NiMh (I read have an initial voltage of 1,45V) it would be 5,8V. Would it give 370lumens or lower?

Regards, Patric

Swedpat said:

Interesting, but do you know what the result will be with 3xCR123 and 9V, which mode will the driver then choose?
Also I earlier wondered about using TK30 with 4AA cells using another extender(may be an unpractical idea because of the length though).
If using NiMh (I read have an initial voltage of 1,45V) it would be 5,8V. Would it give 370lumens or lower?

Regards, Patric

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The threshold is around 7.2 volt, i.e. 3xCR123 will select 640 lumen.
The 340 lumen will be stable down to around 3.2 volt.

HKJ said:

Not the led, but the driver.

The driver has a microprocessor that measures the voltage and then select 370/640 lumen mode.

Click to expand...

So the low flash before turbo comes on should be just as likely with 3 X CR123 as 4 X CR123 right?

Swedpat said:

I still am not sure I understand the advantage of using 3 cells instead of four if the length will be the same, is it mainly for using Titanium triple pack?

Click to expand...

I prefer to run my led lights on primary batteries. I, along with many others have experienced problems with the light not functioning properly when using 4 primary batteries. By removing one cell I was able to smooth out the glitches while retaining seeming full output.

The the peace of mind I get using the triple pack Titanium batteries is just an added perk.

Swedpat said:

Did you measured the output difference between 3 and 4 cells?

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I'm not equipped to do so. I can only say that it appears to be the same brightness as when a I us two 18650s (IMR) and obviously brighter than two CR123.

recDNA said:

So the low flash before turbo comes on should be just as likely with 3 X CR123 as 4 X CR123 right?

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The very noticeable low flash is eliminated when using 3 cells versus 4.

Deputy T. said:

I prefer to run my led lights on primary batteries. I, along with many others have experienced problems with the light not functioning properly when using 4 primary batteries. By removing one cell I was able to smooth out the glitches while retaining seeming full output.

The the peace of mind I get using the triple pack Titanium batteries is just an added perk.

I'm not equipped to do so. I can only say that it appears to be the same brightness as when a I us two 18650s (IMR) and obviously brighter than two CR123.

The very noticeable low flash is eliminated when using 3 cells versus 4.

Click to expand...

Thanks for information!

Then I understand. I don't find the low flash to be a problem, but yes, it would be better without it. And the Titanium triple pack I use as well to my Fenix TA30 and Malkoff MD3 tube, I find it as a GREAT idéa like the double pack. I really hope they never stop making them!

Regards, Patric