Batteries or LED bulb wearing out?

[TeaSipper]

I had my Nitecore P36 since 2015 and I noticed that the beam intensity has weakened. The batteries are Simon but made by Panasonic.

What wears out?

 

[DayofReckoning]

Led's have [FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]extraordinary[/FONT] long lifespans, up to 50,000 hours. Yes, Led's can degrade over time and get dimmer, but unless your p36 has been left on constant for the last 4 years, then it's unlikely to have degraded to any [FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]significant[/FONT] point.

Unless there is physically something wrong with the light, it's more likely to be a worn out cells causing this.

Have you checked the voltage of the cells after resting a period of time from a full charge?

 

[TeaSipper]

No I haven't tried that. Thanks for the tip.

I haven't used the light much in the years but I didn't realize the the LED bulbs have such a long life. The batteries are 5 years old so I guess they degrade. Thanks mate.

I just noticed my join date. I joined the forum to ask what light to get. I got my P36 on July 1 2015. Again thanks for the suggestions, it is a sweet light and very useful. It's a keeper.

 

[LED Monkey]

In 5 years time li-ions will degrade and more or less depending on how the batteries were treated over that time such as if they've been stored for extended periods of time close to fully charged, how they've been charged, what temperatures they have been exposed to and so on. Dendrites will build up inside the cell causing some degree of internal damage. You'll probably notice more so at the higher levels of the light because of internal resistance in the battery. And the battery will still degrade even if you have not used your light very often. The good news is newer batteries are better than ever and cheaper too.

 

[Keitho]

An obvious thing that I miss sometimes---is the lens clean? What looks like minor grime sometimes has a surprising effect on the beam, especially the focus of the beam (grime reflects and scatters light). For batteries, check out http://lygte-info.dk/info/batteryIndex.html if you want to really get the most out of the light with new cells. There is a Nitecore "2900 mAh" cell on that list that will give you 8Wh ea. at 3A down to 3.2V (I doubt that light draws more than 2A), but there are cells like the Sanyo NCR18650GA that will give you >10Wh ea. @3A to 3.2V.

A possible though not likely culprit--the internal thermal regulation has drifted. The light has an internal temp sensor--if it has drifted way out of calibration, it could be causing the light to think it is hotter than reality, and lowering the current to compensate. Another possible but not likely culprit--the battery carrier contacts and/or the battery terminals and/or the contacts between the carrier and the light are dirty enough to increase resistance.

 

[Sovende]

I guess that I'd put a set of new, high quality batteries in before I started taking things apart 😜. If the old batteries have leaked, make sure all points of contact within the battery tube are feee of corrosion to include the rim in the tailcap where the spring rides.
Sovende

 

[TeaSipper]

I have a set of 4 new 18650s in shipment for the new flashlight that's also in shipment. I guess I can try two of them for comparison in my P36. The new Acebeam 18650s are 3100mah are the same as my Simon 3100mah 18650s.

In the meantime I'm charging my Simons so I can check the voltage now and then. Do I need to leave the bats out of the P36 for testing?

And how long after before checking again?