Hi, new here. I'm having an issue with the tail switch on my Nitecore P20. From time to time when I press the switch I get a short blast of momentary on and then when I fully press and "click" the switch the light shuts off. I have an Olight 2600mAh 18650 in it and I swap that battery between my P20 and my Fenix PD35TAC with no issues in the PD35TAC. Any ideas why I could be getting this issue? It's intermittent and unpredictable. I can't find any series of clicks or usage to predict when it will occur. Any suggestions would be appreciated because the UI on this light is one of my favorites. I just can't use a light for LE work that isn't as close to 100% reliable as it can be. Thanks.
Well, first thing to do is loosen the tailcap to it's lock-out position and wait 20 seconds. Then tighten it down, and shield the tailcap a bit and count how many times the red light under the main button flashes. Less than three times and your battery needs charging. If it flashes three times then go buy a can of Electronic parts cleaner from Wal-Mart (in the auto parts dept.) and hose down the threads and tailcap (protect your eyes while doing so) with it and then wipe them down with a clean cloth.
Also double check that the button top on the positive end of the battery is in good shape and hasn't been banged up or anything. Remember that your P20 doesn't have a spring on the positive end due to the way the "reverse polarity protection" works and you could have a cell that is incompatible.
If all this fails try a pair of 123's and drop them in with or without the sleeve to keep em centered. If it works fine then obviously it's your Olight cell. If it STILL has this issue then remove the tail cap and use a length of wire to short the spring on the tailcap to the inside wall of the tailcap where it meets the tube once put together. Hold it for at least ten seconds.
I own a P20UV and I was a bit surprised myself when I first discovered how quickly it drains the battery when using it on high. I suspect you are having issues due to dirty contacts but it could also be that the Olight battery isn't able to keep up with the demand of the Nitecore in high. My own Nitecore 2600 mAh cells work just fine in mine but the real Ultrafire cells I tried (rated 3000mAh) could only keep it lit a few minutes before problems would start.
Also...just thought about it and you should check to make sure the head is tightened fully. Remember that it is also the mode selection method. That too could cause what you are experiencing.
