Nitecore P12 (XM-L2, 1x18650, 2xCR123A/RCR) Review: BEAMSHOTS, RUNTIME, VIDEO+

Rick_R

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The O-ring that I used was a soft one (cheap kit from "Harbor Frieght"). Try taking a knife to the grip-Ring inner edge where the o-ring sits, at about a 45deg. angle (just a small "trim" should help). Or try a smaller dia. o-ring.
I think with 'tolerances in mnfg.' in the body, cap and ring. A 1mm o-ring could be tight on one, and so on another.
Hope this helps.
 

soul347

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The O-ring that I used was a soft one (cheap kit from "Harbor Frieght"). Try taking a knife to the grip-Ring inner edge where the o-ring sits, at about a 45deg. angle (just a small "trim" should help). Or try a smaller dia. o-ring.
I think with 'tolerances in mnfg.' in the body, cap and ring. A 1mm o-ring could be tight on one, and so on another.
Hope this helps.

Alright thanks i'll look into it. I e-mailed nitecore about this and here was their response:

"Thank you for your supports in NITECORE.

The grip ring may be loose, it is designed to be like that as it will not have any scratches on the flashlight body. And even it is loose, but it will not effect the funtion of the ring. Right?

Any questions, please feel free to ask."

I'm not sure if I buy their explanation, but I do realize that the loose o ring is tolerable and still usable.
 

Rick_R

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Alright thanks i'll look into it. I e-mailed nitecore about this and here was their response:

"Thank you for your supports in NITECORE.

The grip ring may be loose, it is designed to be like that as it will not have any scratches on the flashlight body. And even it is loose, but it will not effect the funtion of the ring. Right?

Any questions, please feel free to ask."

I'm not sure if I buy their explanation, but I do realize that the loose o ring is tolerable and still usable.

I can see into thier explanation, there other mnfg.'s using this same grip-ring.
A friend, just picked one up, and the grip-ring was loose from the git-go. He could not use a 1.0mm o-ring (had the same issue as you). Used a .5mm o-ring under the grip-ring. Installed in this order; .5mm o-ring, grip-ring sealing oring and tail-cap. Works great.
FYI- There is a slight bevel allready on the flat side of the grip-ring, for a small o-ring to fit into.
 

soul347

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So I've been using the built-in voltage reader on the P12. How do I know what is low and when I should generally charge my batteries again? I'm using Nitecore 3400 mAh and 2600 mAh 18650 batteries.
 

Rick_R

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So I've been using the built-in voltage reader on the P12. How do I know what is low and when I should generally charge my batteries again? I'm using Nitecore 3400 mAh and 2600 mAh 18650 batteries.

Easy. The blue light in the 'Mode' button will flash, while the light is activated/on. If the battery is very low, it will flash while off.
Note. With li-ion batterys it is best not to run them down to there min. voltage. They like to be topped-off. A li-ion cell fully discharged then charged is a full cycle. Partial discharged then charged is not a full cycle. So in short, the cells last for a longer period of time (i.e. years). But then again, if you use a quality cell, that is capable of 500-600 full cycles, and you fully discharged/charged every day, do the math.
mAh is just runtime.
 

oKtosiTe

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So I've been using the built-in voltage reader on the P12. How do I know what is low and when I should generally charge my batteries again? I'm using Nitecore 3400 mAh and 2600 mAh 18650 batteries.
Generally, 2.8V is considered the very minimum, but 3.2V is a safer cutoff, and recharging at 3.4V is even better.
Below 3.5V the voltage will start to drop quickly, so the runtime between 3.5V and 3.0V is not nearly as long as that between 4.0V and 3.5V.

As Rick_R states above, the mAh has no influence on the voltage at which you should start considering recharging, just on how long it takes to get to that voltage.

Hope that helps.
 
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soul347

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Easy. The blue light in the 'Mode' button will flash, while the light is activated/on. If the battery is very low, it will flash while off.
Note. With li-ion batterys it is best not to run them down to there min. voltage. They like to be topped-off. A li-ion cell fully discharged then charged is a full cycle. Partial discharged then charged is not a full cycle. So in short, the cells last for a longer period of time (i.e. years). But then again, if you use a quality cell, that is capable of 500-600 full cycles, and you fully discharged/charged every day, do the math.
mAh is just runtime.

Thanks for the tip. I didn't know that the mode button will even flash while the light is off? There was a point where it was blinking quite rapidly indicating low remaining power, but that was only when the light was still on. I'll keep on observing
 

soul347

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Generally, 2.8V is considered the very minimum, but 3.2V is a safer cutoff, and recharging at 3.4V is even better.
Below 3.5V the voltage will start to drop quickly, so the runtime between 3.5V and 3.0V is not nearly as long as that between 4.0V and 3.5V.

As Rick_R states above, the mAh has no influence on the voltage at which you should start considering recharging, just on how long it takes to get to that voltage.

Hope that helps.

Thanks for giving precise voltage readings. My light hit 3.5v according to the built in reader and it started flashing rapidly. Is 3.5v considered around 50% battery capacity or less? I think an easier system would be if the light flashed 1-10 times indicating 10-100%.
 

oKtosiTe

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Thanks for giving precise voltage readings. My light hit 3.5v according to the built in reader and it started flashing rapidly. Is 3.5v considered around 50% battery capacity or less? I think an easier system would be if the light flashed 1-10 times indicating 10-100%.

In my experience it is well below 50%. Can't give you any specific number I'm afraid.
 

selfbuilt

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Thanks for giving precise voltage readings. My light hit 3.5v according to the built in reader and it started flashing rapidly. Is 3.5v considered around 50% battery capacity or less? I think an easier system would be if the light flashed 1-10 times indicating 10-100%.
3.5V is nearly fully drained. Typically, you would be about to experience significant output reduction ar this voltage, if you haven't already. Assuming a well regulated light driven at a high level, you really don't have much time left.
If the light had already dropped down to low output, you will have more significant runtime left (at this lower level).

It isn't really possible to give an absolute percentage scale, as a lot depends on what output level you intend to use, and how the circuit responds to low voltage in that mode.
 

Ryp

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At what voltage should I recharge the battery, 3.6/7? Thanks.
 

selfbuilt

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At what voltage should I recharge the battery, 3.6/7? Thanks.
It doesn't hurt to frequently recharge. It's really a question how much reserve capacity do you want left at any given time. Personally, I would recommend recharging a battery once <3.7V - I like to make sure I have a lot of juice left, in case I need it for extended periods.
 

Rick_R

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selfbuilt's comment "It doesn't hurt to frequently recharge". I would agree with. I use the P12 so much, that I re-charge the battery every 2 - 3 days (nights) use. And I carry a spare. When I check the voltage, it's usually beween 3.5v & 3.8v.
After using any light for awhile, you get an idea of when to change-out/charge the cell, whthout contsantly checking volts.
 

Don Sanchez

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Hello there, thanks for this detailed review.

I have a question regarding the step-down on the highest setting. I saw on charts that the P12 steps down fairly quickly after only two minutes or so.
My question is, what happens if the light is put on the highest setting and used for lets say five minutes, then turned off and on again later? Will I have the full 950 lumen again? Is there a wait time or is it dependent on heat or how does this work?
 

Don Sanchez

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Yes, you will have full turbo power immediately upon re-activation

Thanks. I always wondered how the advertised over 1 hour on 950 lumen would work if it steps down. I guess to reach that runtime one would theoretically have to keep turning the flashlight off and on every minute.
Not that anyone would want to do that, but could the flashlight get damaged because of overheating? Is there any heat control mechanism? Or are the step-downs simply timer based?

I could imagine theres a big difference between using the flashlight on a warm summer night right after sunset and a freezing cold winter night with strong winds blowing...
 

selfbuilt

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Thanks. I always wondered how the advertised over 1 hour on 950 lumen would work if it steps down. I guess to reach that runtime one would theoretically have to keep turning the flashlight off and on every minute.
No, the advertised rating includes the step down. The ANSI FL-1 standard measures are independent, and do not imply any sort of continuous set output. The output measure is simply max output between 30 secs and 2 mins post activation. The runtime measure is simply time to 10% of that output on a normal continuous run. If the normal behavior is to step-down, then that is the runtime reported.

No flashlight with a step-down is meant to be run repeatedly/continuously at their highest level.

Oh, and :welcome:
 

KITROBASKIN

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Just to confirm: The Nitecore P12 does not have a low voltage disconnect, right? Since I use it on a headstrap it may very well be that the flashing button will not be seen. By the time the light is noticeably dimmer I'm guessing the battery is discharged beyond 'good practice'.

Typically, I charge batteries when they get to the 3.8-3.9 voltage range but am now using unprotected cells in the P12 and was wondering if there was an LVD as a failsafe.
 

MightyBright

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Does anyone have experience carrying this in a pocket or clipped to a belt? How did it work out?
 

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