And the Nitwcore batteries that came bundled with my Nitecore i4 Charger
In my HC30 headlamp, the Samsung’s seem to work initially, but in 10 minutes or less of continuous operation at full brightness the light output drops to about 1/4 of full without me doing anything.
If I turn the headlamp off and leave it off for a few minutes, then turn it back on, the process repeats.
At first I thought the HC30 was faulty, but when I use the Nitecore or Panasonic batteries in it, I don’t suffer the same problems. As a result I can only conclude that the Samsung batteries I got from Fasttech are either fake and/or crap.
But the HC30 does step down automatically! No light will give 100% all the time the ANSI test does not require the light to! so for greater battery life and thermal protection the torch will step down.
How many MAH are the batteries?
They are 2500mah (the ones that show obvious dramatic stepdown).
The 3400mah Panasonics probably step down, but nowhere near as dramatically. Same applies to the 2600mah Nitecore batteries. It’s just the Samsung’s that show massive drop down quite quickly.
There’s a couple of ‘analyzing’ chargers around that price eg; Opus BT-C3100, that have a voltage readout, & will give you a good idea of a cell’s capacity, & internal resistance.
Alternatively, something like the UNI-T ut210e multi meter will test the voltage more accurately, & allow you to take current draw readings, to gauge the performance of a cell (as a part of the circuit) in use.
The Samsung 25R batteries are pushing the juice harder than your other cells (as expected).
This is causing your light to go into thermal regulation faster. It’s not bad batteries at all. If you had a way to measure brightness (not by eye sight), you would likely see the light is brighter with the 25R’s. Unless the drivers is just wasting the extra current/voltage……
@Greatwhitehunter,
You are "lucky" if they are even working in the Nitecore HC30 as the Samsung INR18650-25R batteries are Flat Top.
Virtually all Nitecore lights have mechanical reverse polarity protection, so they require Button Top batteries.
I have found that rarely Flat Top batteries have worked in some of my Nitecore lights, but they stop working a short time later. And in later attempts, they don't work any longer.
I think you may have a Nitecore HC30 that will borderline work with Flat Tops, but as others mentioned it is driving it harder so that you are getting thermal stepdown.