Defective Nitcore TM26?

Hey guys,

I've just received my new toy but for some reason, the light doesn't always turn off properly when the switch is fully depressed but instead changes modes or turn off and back on instantly. Press the button quickly and firmly seems to solve this problem but it's a pain in the *** that wasn't there on my TM11. Also, charging all 18650 batteries with the provided charger only charges to 4.11 V according to my DMM so I'm seriously considering asking for a replacement unless there is something that can be done about it.

Dimitri Stephan said:

Hey guys,

I've just received my new toy but for some reason, the light doesn't always turn off properly when the switch is fully depressed but instead changes modes or turn off and back on instantly. Press the button quickly and firmly seems to solve this problem but it's a pain in the *** that wasn't there on my TM11. Also, charging all 18650 batteries with the provided charger only charges to 4.11 V according to my DMM so I'm seriously considering asking for a replacement unless there is something that can be done about it.

Click to expand...

Ref end-of-charge voltage: Many in-flashlight charging circuits err on the side of safety and end their charge at distinctly less than the presumed full-charge of 4.20 volts. If you skim thru the posts on the TM26, many people have observed that the TM26 ends it's charge cycle rather early. On the plus side, your expensive cells will last longer. Check out the various posts on 18650 cells and life vs end-of-charge voltage, if not directly on Battery University. I have two TM26s (old/new) and both end their charge at 4.15 or even less. I generally do not use the TM-26 charging system to charge the cells since I want to observe the charging behaviour of the individual cells. Charging all cells in parallel hides that important factor.

Another point is calibration of DMMs. Look at the specs on your DMM and calculate a worst case reading. You may be surprised. There are 'accurate' 3-1/2 digit DMMs and there are not-so-accurate 3-1/2 digit DMMs. Generally money spent for a DMM above about $50 results in higher accuracy. There are $10 3-1/2 digit DMMs. I have both. The TM26 also has the question of voltage calibration.

Ref the TM26 switch: The later TM26s have a different clicky feeling than earlier models. That includes both the on/off and the softer mode changes. If you can clearly hear a click and the light still refuses to shut off, then return it. or if the switch has a mushy feeling for the on/off. The mode changes may seem mushy during any change in output lumens. The TM-11 switch has a very different feel than the TM-26 switch.

I really don't mind if the light stops charging the batteries at 4.13 V. The switch is the real issue here. It HAS to turn off when I want it to not change modes or go off and back on immediately. I could probably replace my TM26's switch with my TM11's switch but I haven't found a way to gain access to the board. What to do?

Dimitri Stephan said:

Hey guys,

I've just received my new toy but for some reason, the light doesn't always turn off properly when the switch is fully depressed but instead changes modes or turn off and back on instantly. Press the button quickly and firmly seems to solve this problem but it's a pain in the *** that wasn't there on my TM11. Also, charging all 18650 batteries with the provided charger only charges to 4.11 V according to my DMM so I'm seriously considering asking for a replacement unless there is something that can be done about it.

Click to expand...

As far as I know, those are normal traits of the TM26. The in-light charger doesn't fully charge batteries. Whether that is a good or bad thing, it is a thing for the TM26.

And the electronic switch UI has a very fast momentary, so a quick press on the switch is needed to turn it off. Even then I tend to have the occasional accidental mode switch. I agree that it can be annoying but I don't think your unit is different/malfunctioning.

If anything, we both probably need to get use to the UI a little more.

I can turn my light off 3/4 times. The 4th time the light either switched modes or turns off and back on immediately. I haven't had this problem with my TM11 at all so I don't see why this should be happening now.

Without having proof, I believe my tm26 switch got better with use. Possibly, familiarization with the subtleties of button pushing on that model played a factor. Heavy gloves in cold temperatures makes operation much more clumsy, though from what you are saying it does not sound like the problem is you. If it was me, I would go to near the limit of being able to return it to see if the switch begins to behave consistently. Good Luck.