Problem with my new Astrolux S41

I just received the rainbow alloy S41 from Banggood today. I have some unprotected 18350 cells on the way, but in the meantime I've got some 16340's. One is a Nitecore 600mAh and the other is a 700mAh Keeppower. Both are protected cells.

Something odd is happening with the Keeppower cell. When I put a fresh Keeppower 16340 in the light, I can't access turbo, it quickly flashes and goes dark. Try cycling back to turbo and the same thing happens. But as the cell gets used up while I use the light on other modes, I can then access turbo and it works. It's as if as the voltage of the light goes down with usage, the light
let's me access turbo mode. The cell in question shows 4.16 or so volts when I take it off the charger.

Whats is is going on?

It COULD be that the higher voltage of a fully charged battery is pushing sufficient current to trip the protection circuit. But after voltage has dropped with some use, current draw drops below that which trips protection. Use of an unprotected battery (one which can handle the current draw) will confirm whether or not this is the case.

Another thing to keep in mind with this light is that it doesn't work especially well with small cells - especially on the higher modes. The higher modes EASILY draw more current than most 16340s and 18350s can provide. If you wish to run the light on the higher modes (especially for extended times), it is best to get the extender and run the light on an 18650. Higher draw cells (like the NCR18650GA, NCR18650BD, or even true high draw cells) work best.

I hope it is just that... and not a broader quality issue.

I just received mine and am disappointed. One led is dirty and blue. I've contacted CS at BG, so we'll see where it goes... but for a new light, kshdjdksjsjshsjsnsnss! oundingonkeyboard:

Very interesting indeed. I had same problem with my Nitecore TM06S. Except that it only does that in certain modes -- it had lower, low, med, high, turbo modes. With some set of freshly charged batteries of LG HE2 and LG DBMJ1, it always "crashed" and restarts in low and high modes. But never in lowest or turbo modes. I had to run it on turbo using long press shortcut for 30-60 secs, and all modes will work fine.


It doesn't happen on my newly arrived Samsung 30Q which is on its first charge.


At first I thought it was voltage sag, i.e. too much deltas on 4.2V charged battery. But I think StorminMatt guess also makes sense. I'm not really familiar on how flashlight protection trips works. Does it only disconnects the circuit in milliseconds? Mine really seems like momentarily underpowered circuit.

It is unlikely that a protected 16340 can provide sufficient current and voltage. In turbo the light turns on the FET and gives the FOUR LEDs as much juice as they can get. Would easily overwhelm your 16340s. I hope the 18350 you bought is an IMR

From my personal exp, that is a bad phosphor/dedome job

What LED option did you chose?

Nichia 219b

I too chose the Nichia 2019b, and I guess I was fortunate that all of my LED's look fine. My god this light weighs a TON! I understand that is due to all the copper in the head.

And this is the battery I ordered from Illumination Supply: [h=1]18350 Keeppower IMR18350 750mAh High Discharge Flat[/h]

My understanding of the blue LED issues is the poor install of the optic that led to damage of the LED's dome causing essentially a dedome. If you don't have that issue I suggest not taking it apart as it might cut the dome on the LED and cause the issue seen above.

That is a good cell, I have four of them and they work wonderfully with my S41. My other thought was a broken FET on th driver but as the cell gets used it cannot drive hard enough to potentially trip or have the protection interfere with the output.

staticx57 said:

My other thought was a broken FET on th driver but as the cell gets used it cannot drive hard enough to potentially trip or have the protection interfere with the output.

Click to expand...

Can you elaborate on this some more? Is my understanding correct in that my protected 16340 has too much voltage when it come off the charger, that it trips the defective FET? But as the cell is depleted with use, the cell no longer trips the FET and I can access Turbo at that point? I am able to access turbo with the protected Keeppower 16340 after some use, just not when I insert a fresh cell off the charger.

I understand the FET drawing so much from the protected cell that the protection kicks in and cuts the cell output off. But I am confused as to why the protection would stop working once the cell was somewhat depleted and then allow me to access Turbo. On a fresh cell I can't access turbo or the tactical strobe, I forgot about the strobe until just a moment ago.

Taxman said:

Can you elaborate on this some more? Is my understanding correct in that my protected 16340 has too much voltage when it come off the charger, that it trips the defective FET? But as the cell is depleted with use, the cell no longer trips the FET and I can access Turbo at that point? I am able to access turbo with the protected Keeppower 16340 after some use, just not when I insert a fresh cell off the charger.

Click to expand...

Your FET is likely fine. I was talking about the cells protection circuit. The FET is probably trying to pull too much current and the protection stops it. The sole purpose of the FET is to let the LEDs draw as much current as possible, hence Turbo. This likely far exceeds the protection threshold. As the cell is depleted it cannot even try and deliver enough current that would trip the protection.

This is also why IMR cells are better suited to this light (or INR 18650s but those don't exist in the 18350 world) as they can supply way more current than the LED would draw and would hold their voltage better leading to a more efficient driver and longer run times. At least if you use the turbo setting often. Low current draw IMR becomes not so necessary as you can tell already.

Thanks staticX, I understand now. I should have the IMR 18350's in a few days. Also, I will obtain an 18650 tube for this light and utilize the 18650GA's I currently have for my Zebralight SC600 MkIII HI.

Mine behaved the same way when i test it with a aw 16340. It's the protection in the battery. No issues with those keeppower imr 18350, or high drain 18650. All my leds got the same tint.

Yea it got De-domed some how. The phosphate layer is gone. I hope they give you an new one no hassle Shipping on this would be painful!

hazard2036 said:

Yea it got De-domed some how. The phosphate layer is gone. I hope they give you an new one no hassle Shipping on this would be painful!

Click to expand...

Thanks guys. I've sent in the contact form from the mobile site. Hopefully I'll hear something positive back soon. If not I might PM them on here.

Taxman said:

Thanks staticX, I understand now. I should have the IMR 18350's in a few days. Also, I will obtain an 18650 tube for this light and utilize the 18650GA's I currently have for my Zebralight SC600 MkIII HI.

Click to expand...

The 18650 tube is definitely a MUST HAVE with this light.

Taxman said:

Something odd is happening with the Keeppower cell. When I put a fresh Keeppower 16340 in the light, I can't access turbo, it quickly flashes and goes dark. Try cycling back to turbo and the same thing happens. But as the cell gets used up while I use the light on other modes, I can then access turbo and it works.

Click to expand...

This is almost exactly what is happening with my Nitecore TM06S, on some sets of batteries, but not the others! On mine, I can't access the low and high. Lowest (3 lumens) and turbo worked fine. So I had to run it in turbo for a good 30 secs to drain the battery a bit to 3.9-4.0v and afterwards everything will work fine.

But I'm not sure if mine had the same root cause. All my sets are unprotected 18650

I think I'll post a new thread regarding this.

Bdm82 said:

Thanks guys. I've sent in the contact form from the mobile site. Hopefully I'll hear something positive back soon. If not I might PM them on here.

Click to expand...

hazard2036 said:

Yea it got De-domed some how. The phosphate layer is gone. I hope they give you an new one no hassle Shipping on this would be painful!

Click to expand...

Just thought I'd give an update... after sending several pictures in of the problem, Banggood agreed to send me a replacement head free of charge. It was backorder for a short period but arrived yesterday and works great. All worked out fine in due time.

Very good. Manker customer service is top notch