Klarus service (China) has replied to my email query if the XT11 can use 2x18350 cells. Below is their reply:
Helloi am sorry , 2*18350 also can be safely uesed in the XT11,it will fit in the cell compartment
best regards
Now the question is: Which is better and safer.. the 2x RCR123a (ICR) or the 2x18350 IMR. Both at about 750mAh.
What about 2 x primary 3V 123s vs 2 x 3.7V RCR123s vs 1 x 3.7V 18650 vs IMR cells.
Which of these would be the best all round battery choice and other considerations?
We have seen the differences between 1 x 3.7V 18650 vs 2 x 3.7V RCR123s.
The RCR123s are rated between 3.2V and 3.7V usually and primary 123s are only 3V normally.
This Klarus XT11 is rated to a maximum working voltage of 8.4V.
So even 2 x 3.7V RCR123s straight off the charger at around 4.2V each is not going above the maximum working voltage of this flashlight.
I have noticed the big difference already by using 2 x 3V 123 primary batteries.
So I would expect to see more brightness with 2 x 3.7V RCR123s than using just 2 x 3V 123 primaries as shown in the beamshots in this thread.
It would mean some different voltages can be used in this flashlight with different outcomes.
1 x 18650 = 3.7V or 4.2V hot off the charger.
2 x CR123s = 6V.
2 x RCR123s = 7.4V or 8.4V hot off the charger.
I would have thought this light would regulate itself to a maximum limit of lumens no matter what the input voltage was.
It does not seem be that way to me.
Also there is of course the runtime you can get from these formats and do so reliably.
So there is runtime vs output to consider in this situation.
I will test that out for myself as soon as I get hold of two 3.7V RCR123s and also some IMRs.
Then there is the regulation of what it cuts the lumen output to when running at 7.4V or 8.4V.
Will the operating temperature stay at a safe level when using 7.4V or even 8.4?
I assume that the pictures in the beamshots were taken before the 3 minute kick down regulation cut in and therefore at maximum brightness.
Can CPF user
Adrenaline 6 tell us whether all the pictures were taken before the 3 minute kick down regulation started?