Object/Subject Review: Sunwayman T20CS

[Helmut.G]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Ok, I know nothing but here's what I'm thinking and I tried starting a thread about that without too many good answers. There must be a certain voltage (maybe 3.6 volts I don't know) where circuitry on the Ti2 says: "okay! we're dealing with a 16340 here, let's suck all the voltage AND amps we can out of this battery, but no more than we need to get us to 500 lumens." If it wasn't limited to 500, I could stick AW IMR's which do 8C and I'd get 900 lumens, who's with me?

It's quite simple:

The circuit in 1xCR123 lights (and in 1xAAA, 1xAA, 2xAA) needs to increase the voltage it gets from the battery.
This is called boosting.
There are also buck-circuits, lowering the input voltage (e.g. in 2xCR123 or 3xCR123 lights).

This is needed because white LEDs need a certain voltage to shine brightly, and this voltage is (depending on the LED type, individual LED and desired current through it) slightly to very significantly higher than the battery's voltage under load.

Now LiIon batteries have higher voltages, and a fully charged LiIon will exceed the voltage needed to power up most LEDs used in Flashlights.
There are LED drivers in flashlights that can both step up and step down the input voltage, but they are very rare.

Most boost circuits simply let the LED run directly from the battery (or batteries) once the battery's voltage under load reaches the needed LED voltage for the desired output level.

Now you need to know that LEDs will increase their current very fast as you give them more voltage.

Here's an example from jtr1962's most excellent LED lumen testing thread:
A Cree XP-G tested needed 3.01 V to run at 0.350 A.
At 3.50 V, only at 16% increase the LED ran at 2.5 A (a 714% increase).

Note that every single LED will vary here! If you buy two XP-Gs or XM-Ls they will not have the very same current vs voltage curve.

Now you see that XP-Gs have a pretty low Vf (forward voltage) compared to the 4.2 V of a Lithium Ion, and XM-Ls are similar.

The only thing that protects these LEDs from burning out when you use them with an RCR123 in this way is the internal resistance of the battery.
If you'd connect the LED to a lab power source than can sustain high currents and hold the voltage at 4.2 V, instant would be the result.


So, Lou Maan, if you run your light with an IMR battery you should indeed get more current through the LED because the IMR has a lower internal resistance.
Be aware that the higher you push the current, the smaller the resulting difference in output gets so it might not be worth it.
At some point (that is determined by the LED type and the heatsinking) the LED will even produce less light if you raise the current further.
If you are interested in this look into the Lumen testing thread linked above.

Btw the more extreme currents you use the greater the difference between LED lumen output bins gets. While a T6 binned and a U2 binned XM-L will be extremely close in output at low and standard currents, if you push them to the max the difference could become significant because less heat produced (and the higher bin will produce less heat) means lower LED temperature and thus higher efficiency.


Not all LEDs are created equal. If you go into extreme territory the differences will show.


Lou Maan, is your V10R Ti equipped with an XP-G? The XM-L has a lower Vf so it should run noticeably brighter in direct drive with an RCR123.

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

It's quite simple:

The circuit in 1xCR123 lights (and in 1xAAA, 1xAA, 2xAA) needs to increase the voltage it gets from the battery.
This is called boosting.
There are also buck-circuits, lowering the input voltage (e.g. in 2xCR123 or 3xCR123 lights).

This is needed because white LEDs need a certain voltage to shine brightly, and this voltage is (depending on the LED type, individual LED and desired current through it) slightly to very significantly higher than the battery's voltage under load.

Now LiIon batteries have higher voltages, and a fully charged LiIon will exceed the voltage needed to power up most LEDs used in Flashlights.
There are LED drivers in flashlights that can both step up and step down the input voltage, but they are very rare.

Most boost circuits simply let the LED run directly from the battery (or batteries) once the battery's voltage under load reaches the needed LED voltage for the desired output level.

Now you need to know that LEDs will increase their current very fast as you give them more voltage.

Here's an example from jtr1962's most excellent LED lumen testing thread:
A Cree XP-G tested needed 3.01 V to run at 0.350 A.
At 3.50 V, only at 16% increase the LED ran at 2.5 A (a 714% increase).

Note that every single LED will vary here! If you buy two XP-Gs or XM-Ls they will not have the very same current vs voltage curve.

Now you see that XP-Gs have a pretty low Vf (forward voltage) compared to the 4.2 V of a Lithium Ion, and XM-Ls are similar.

The only thing that protects these LEDs from burning out when you use them with an RCR123 in this way is the internal resistance of the battery.
If you'd connect the LED to a lab power source than can sustain high currents and hold the voltage at 4.2 V, instant would be the result.


So, Lou Maan, if you run your light with an IMR battery you should indeed get more current through the LED because the IMR has a lower internal resistance.
Be aware that the higher you push the current, the smaller the resulting difference in output gets so it might not be worth it.
At some point (that is determined by the LED type and the heatsinking) the LED will even produce less light if you raise the current further.
If you are interested in this look into the Lumen testing thread linked above.

Btw the more extreme currents you use the greater the difference between LED lumen output bins gets. While a T6 binned and a U2 binned XM-L will be extremely close in output at low and standard currents, if you push them to the max the difference could become significant because less heat produced (and the higher bin will produce less heat) means lower LED temperature and thus higher efficiency.


Not all LEDs are created equal. If you go into extreme territory the differences will show.


Lou Maan, is your V10R Ti equipped with an XP-G? The XM-L has a lower Vf so it should run noticeably brighter in direct drive with an RCR123.

Very interesting! Thanks that's a lot to take in but that's why I'm here . I have the V10R (T6) and the V10R Ti2 (U2), and there's just such a huge difference using even the same battery. (I know because I have two RCR's and when I swap, the U2 is still so much brighter.) It's not just a dud T6 either, I have 3 of the T6 ones 2 U2's and the story is the same right across.

 

[Lou Minescence]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Great job Bigmac. Very informative and presented well. Selfbuilt may have some competition. I was looking for some vocal narration on the you tube video. Just a thought. Thank You.

 

[Bigmac_79]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Great job Bigmac. Very informative and presented well. Selfbuilt may have some competition. I was looking for some vocal narration on the you tube video. Just a thought. Thank You.

Thanks for the encouragement and the advice!

 

[Bigmac_79]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Outdoor beamshots added! Very impressive throw, lit up a silo at ~1/3 mile.

 

[Bigmac_79]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Alrighty, white wall beam shots added and "Thrower" subjective review added.

This review is complete, with long term impressions pending!

:thumbsup:

 

[RCLumens]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Excellent review BigMac - through & through (even though the light threw) haha - sorry just a bit of scotch talking after some guests departed... Great review and is very useful! So the throw certainly seems worthy, especially given the size. I wish I had the resources to do a comparison between this and the TK21 - perhaps I will - but I think I'm going to pick up a t20cs in January regardless. Tough to beat this throw in a package so small. Any longer term impressions are always welcomed!! Cheers and Happy New Year to all! Excellent review BigMac!

 

[phantom23]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

It's just a shame that the performance on 1x18650 is not better than I expect. Assume it's because of the wide working voltage(2.5~10V).

P.S : But T40CS shows the flat regulation with 18650's in spite of 5.5~16.8V working range. :shrug:.

Wide voltage range doesn't mean it has to be unregulated. It seems that T20CS driver has a huge dropout voltage (difference between the input voltage and output voltage to remain constant output current), even AMC7135 is better. Most producers try to reduce it but obviously Sunwayman has decided to optimize T20CS to 2xCR123A. Weird thing it - they failed...

T40CS uses 2x18650, that's 8,4V when fully charged and 5,5-6V when discharged.

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Alrighty, white wall beam shots added and "Thrower" subjective review added.

This review is complete, with long term impressions pending!

:thumbsup:

Good stuff Bigmac! Well done and as objective as possible whilst still giving us some feedback to work with . Sounds like it throws well enough and the smaller head means more pocketability. In a defensive situation, that would be tons more than enough to keep the assailant at a distance and at least the hotspot isn't so small that you can only aim it precisely in one eye at a time . Ouch!

That silo being 1/3 mile away, that's about 586 yards! And don't forget the light that hits the object has to make it back to your eye for you to perceive it. So that light has traveled 1172 yards and probably far beyond. I'd say that classifies as a thrower, yes indeedeedoo.

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

@ Bigmac

What I am posting today really sucks and I think there may be a major recall on these lights. I've just started a thread on this problem but I thought you (and Sunwayman) should be the first to know since I know you have one too. Anyway, let me know how you go please. I can't believe no one else has noticed this yet but now a buddy a mine says his light does exactly what mine does... anyway, here's how the post goes:

Hi, got my T20CS this week and everything seemed to work fine at first. Then one night I decided to pretend I was in a real life tactical situation and double clicked for strobe. After about 5 seconds the light turned itself off. I was like: "What the? Did that just happen?" Clicked it once more and it returned to strobe for half a second then went off again. Everything was tight, tested my battery and it was good, changed the battery today and it's doing it consistently except it goes to low after. I have good batteries and the strobe is only on high, it's not like it's a turbo strobe so the batteries can sure handle a sub 500 lumen strobe. Just glad I tested it before trusting my life to it. Okay, maybe I'm jumping the gun here but is there something I need to clean, is it just a dud, or should I be using something else as a tactical light because side switch electronics just do that (malfunction)?

Just for reference, my T40CS malfunctions too but only when I'm on low, I go to switch it off with a single click and strobe kicks in. I'm not riding the switch with my finger or anything, it's clearly off, I know how to properly/cleanly click buttons, been using buttons all my life on computer/Nintendo/X Box whatever so I really do think there is a problem with this configuration. The only thing that's never let me down is my T20C which has a completely different switch system (and a nice strike bezel I might add. Is anyone else experiencing this problem or is it just me? Can I do something to fix it?

Addition: It only happens if I depress the rear switch and turn it off, then turn it back on again via the rear switch (ie fresh start) then program it to low, turn it off from the side switch, then turn the strobe on from the off by double clicking. Then it turns itself off after a 5 second strobe. Alternatively, if I leave it on turbo then turn it off on the side, if I double click from that off position, there is strobe for 5 seconds and returns to high or turbo (hard to tell). Hard to explain because of the UI is complex but I hope some guys get what I mean and try it to see if it happens to them. Thanks.

 

[Mikellen]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

One question... When the flashlight tail switch is in the off positon, and the batteries are low, will the red led low battery indicator start to blink? If so then that would not be very good in a tactical situation when it is important for an LEO's position not to be given away.

Example: If the batteries were not as fresh as they should be and a LEO (law enforcement officer) is conducting a building search for suspects. In this case the LEO would most likely only use short momentary bursts of light in order to reduce his or her position from being noticed. The LEO does not want the light on for any length of time or anything else that could give their position away to the suspect(s). So if the low battery indicator starts to activate (indicating low battery) then that could place the LEO in a compromising position.

Is there an option to disengage the low battery indicator? If not then in my opinion the LEO would have to be sure that the batteries have enough stored energy in order to avoid the LBI's blinking light from coming on and possibly jeopardising the LEO's safety. I personally have conductd many of these types of searches and would not use a light that has a low battery indicator. My thought is, even if the batteries were fresh its possible that the LBI can malfunction for whatever reason and start to activate.

Edit: If the LBI can only activate when the flashlight is on and will immediately deactivate as soon as the tailcap switch is disengaged then my concerns above are alleviated some. I still would prefer not to have the LBI because I think that the more features that are incorporated in a device then the greater chance for reliability issues. (Just my 2 cents).

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Your LBI won't activate if your tailswitch is disengaged. In fact, it won't blink unless your light is on full stop.

ps. Who's Leo?

 

[Mikellen]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Thanks for clarifying the low battery indicator activation.

LEO= Law Enforcement Officer.

 

[RCLumens]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

This stinks... Did you run into the same on yours BigMac? I'm so close to getting the light, but this might be a deterrent. Thanks for the info though Lou, It would have bummed me out, or worse, had you not posted this. Definitely appreciated!

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

You're welcome RCLumens. I can't say I'm as excited about this light as I was when I opened the box.

 

[RCLumens]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Sorry to hear that Lou... How's everything else functioning? Throw, etc...? I've got a thread on here looking for this sized light as I'm also looking at the scorpion with Turbo head, and quite actually perhaps a Sunwayman V60C - I know it's a bit bigger, but the form and weight are not too bad - and the light will throw well. Any comparisons to the T20CS with your other lights? Cheers, RC

 

[Lou Maan]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Yeah, RCLumens, everything else works as it should. I guess it's still usable, you just don't use strobe from the off position which is a downer (and a deal breaker for me, mine's going back to the dealer and there are going to be a lot of very annoyed dealers out there now). You can blind the bejesus out of someone with the tail clicky. It's about 3-4 times more throwy (brighter hotspot) than the T20C, which itself is a VERY capable light. The hotspot isn't too small which means it's not hard to aim at something/one. Cool green tint, no donuts. Usually small-headed lights that throw like this one have narrow spill but it actually has decently wide spill so Sunwayman have figured out how to do that with this particular reflector design. They could easily develop a moderate size triple using this design of reflector that throws like crazy. Best reflector shape I've seen for XM-L. So wider spill than V20C, T20C. Now the V60C is a highly underrated light. It's compact enough but heavy and if you don't have big hands, it can get a bit tiring but it's fine for an hour or so. (Sorry moderators I know this is a T20CS review but someone asked to compare so I think it's appropriate). The V60C has a beautiful wide spill (wider than T20CS) and the hotspot will absolutely waste the T20CS in a throw/bright hotspot competition. Batteries seem to last forever because there are 3. I've only charged mine once to try the charger in 2 months. You can also keep the batteries in there if you have a charger because you can test voltage directly from the tail contacts!! They're both nice camping lights, depends on how much power/size/distance you need. I can't wait to hear more feedback on the switch issue.

I have a Ultrafire U80 which throws incredibly and has a 44mm head. The little SWM T20CS which has a 36 head I think gives it a run for its money and possibly beats it in throw. Hard to tell but very close. The T20CS is more pocketable and less aggressive looking. I'm thinking SWM will want to fix this problem because it's a good light in all other respects.

 

[RCLumens]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Many thanks again Lou! Great information! I'm relatively close to the folks at battery junction, so I drive there to pick up my lights and am able to compare form factors as I usually make the trip in the morning amid don't really have the chance to do beam comparisons. I'll be comparing the t20cs and will check out the strobe function while there - that could also be a deal breaker for me also. I'll also be comparing it with the scorpion v2 and the v60c. Anyway, perhaps I'll open up another topic/thread as I apologize for taking this one somewhat off topic. However, the t20 cs is certainly a contender, and this thread has been most helpful. Thank you and thank you to all the members here. Rc

 

[Rokron]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

I've had my T20CS for 2 weeks now and I use it all the time including the strobe, the light works flawlessly. But after reading about the problem, I duplicated the same thing with my light.
Myself, I don't concider it a problem, the light works per the instructions. Who knows, this just might be normal for this light. We shall find out soon enough. It's still one darn nice light and would concider buying another one for Cerakoting.

 

[RCLumens]

Re: Object/Subject Review: Sunwayman T20CS (In Progress)

Thanks for the in for Rokron, definitely notated, and very useful info!