【convoy】M21G XHP70.3 HI 2*21700 flashlight available

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Haukkeli
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I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Alen
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Simon,

I want see which of these drivers is less bright.
Can you post a photo comparison between the13 group driver powered by Ni-Mh AA batt.

https://aliexpress.com/item/1005003374477862.html

and the 4×7135 new firmware driver powered by lithium?

https://aliexpress.com/item/32734523412.html

Both drivers set at minimum level brightness with same Led type

Thanks

4x18a
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Haukkeli wrote:
I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Could you please share how to mod 25A ?

Haukkeli
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4×18a wrote:
Haukkeli wrote:
I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Could you please share how to mod 25A ?


Just by lowering current sense resistor value. If you remove the driver it has 2 big resistors with R020 written on them. So 10mOhm for 18A. From there you can calculate sensing voltage. Knowing the voltage you just change the amperage to your desired value in U=RI equation.
U=10mOhm*18A-> U=180mV.
R=U/I-> R=180mV/25A-> R=7.2mOhm.
Edit: I have tested it to function with 25A, but there’s always risk for something to break.
4x18a
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Haukkeli wrote:
4×18a wrote:
Haukkeli wrote:
I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Could you please share how to mod 25A ?


Just by lowering current sense resistor value. If you remove the driver it has 2 big resistors with R020 written on them. So 10mOhm for 18A. From there you can calculate sensing voltage. Knowing the voltage you just change the amperage to your desired value in U=RI equation.
U=10mOhm*18A-> U=180mV.
R=U/I-> R=180mV/25A-> R=7.2mOhm.
Edit: I have tested it to function with 25A, but there’s always risk for something to break.

Thank you very much ! I have removed the switch and 2 screws but the driver still too tight can not get it out , I missed something ?

Haukkeli
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4×18a wrote:
Haukkeli wrote:
4×18a wrote:
Haukkeli wrote:
I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Could you please share how to mod 25A ?


Just by lowering current sense resistor value. If you remove the driver it has 2 big resistors with R020 written on them. So 10mOhm for 18A. From there you can calculate sensing voltage. Knowing the voltage you just change the amperage to your desired value in U=RI equation.
U=10mOhm*18A-> U=180mV.
R=U/I-> R=180mV/25A-> R=7.2mOhm.
Edit: I have tested it to function with 25A, but there’s always risk for something to break.

Thank you very much ! I have removed the switch and 2 screws but the driver still too tight can not get it out , I missed something ?


Wires to led are holding it in place. And maybe to switch also.
4x18a
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Haukkeli wrote:
4×18a wrote:
Haukkeli wrote:
4×18a wrote:
Haukkeli wrote:
I modified my driver to 25A output. TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation. In my tests those Liitokalas give little over 7A in direct drive lights and 18A/4 is 5.5A. Maybe enough to cause voltage to sag.

Could you please share how to mod 25A ?


Just by lowering current sense resistor value. If you remove the driver it has 2 big resistors with R020 written on them. So 10mOhm for 18A. From there you can calculate sensing voltage. Knowing the voltage you just change the amperage to your desired value in U=RI equation.
U=10mOhm*18A-> U=180mV.
R=U/I-> R=180mV/25A-> R=7.2mOhm.
Edit: I have tested it to function with 25A, but there’s always risk for something to break.

Thank you very much ! I have removed the switch and 2 screws but the driver still too tight can not get it out , I missed something ?


Wires to led are holding it in place. And maybe to switch also.

I removed all wires to led , switch , 2 screws but the driver still not move . Can you remember how to get it out ?

tactical_grizzly
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Haukkeli wrote:
TacGriz, did you use included Liitokalas on your testing? It could be that it is regulated, but battery voltage just sags enough for it to drop out of regulation.

I used NCR18650GA’s for my testing but I think your explanation is correct. As the cells are depleted, the voltage will sag lower, and eventually it sags lower than the LED’s Vf so you cannot get full brightness.

That’s been my experience with all the SBT90.2 lights I’ve tested that have one cell, or multiple cells in parallel. I think SBT90.2 is best driven my multiple cells in series with a high current buck driver like in Convoy L7.

Haukkeli
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It’s probably just little stuck. There wasn’t any glue in mine. Try to wiggle it little from switch hole and usb-c port.

ArtieT59
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tactical_grizzly wrote:
I think SBT90.2 is best driven my multiple cells in series with a high current buck driver like in Convoy L7.

 

I couldn't agree more!

 

The L8 is definitely my favorite single cell sbt90 Light. I like everything about it, but the biggest drawback is the limited compatibility of a single 26800 / 26900. They're just not great cells for high amp sbt90 lights. I'd much rather the L8 head / Reflector with single 21700, 21700 in series or even 26800 in series if need be, and the appropriate buck driver of course (Side switch only). But, i still use the L8 daily and own two of them. One for each hand, of course.

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100

The BLF GT with SFT40 (2300lm, 2700m+ @ 30 seconds!)
https://budgetlightforum.com/node/79561

BlueSwordM
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Or better yet, just use higher power cells like the Samsung 30Q or Molicel P28A.

The NCR18650GA is a 5-8A cell at best honestly, and going at 10A isn’t the best idea to get out most capacity out a high power LED.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Tatteredmidnight
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BlueSwordM wrote:
Or better yet, just use higher power cells like the Samsung 30Q or Molicel P28A.

The NCR18650GA is a 5-8A cell at best honestly, and going at 10A isn’t the best idea to get out most capacity out a high power LED.

As someone mentioned above, at 18A, it should be pulling about 4.5A per cell, which may cause sag in an NCR18650GA, but should be well within its capabilities. Probably less at most voltages since it’s a buck converter and the vF is close to 3v, so at higher cell voltages, it should be pulling less than 4.5A for the driver to deliver 18A @ 3v.

Haukkeli
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Even at 25A it’s only 6.25A per battery, which should also be ok for Sanyos. Sbt90.2 is about 3.6V on 25A if extrapolating from diagram. And GA’s drop to 3,8V at 7A current draw.

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Tatteredmidnight wrote:
BlueSwordM wrote:
Or better yet, just use higher power cells like the Samsung 30Q or Molicel P28A.

The NCR18650GA is a 5-8A cell at best honestly, and going at 10A isn’t the best idea to get out most capacity out a high power LED.

As someone mentioned above, at 18A, it should be pulling about 4.5A per cell, which may cause sag in an NCR18650GA, but should be well within its capabilities. Probably less at most voltages since it’s a buck converter and the vF is close to 3v, so at higher cell voltages, it should be pulling less than 4.5A for the driver to deliver 18A @ 3v.

4×18A’s driver is linear, not buck

Also, max achievable turbo brightness drops smoothly as the batteries drain so it makes sense that voltage sag is the cause.

Chinaheart
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Happy Birthday Simon Mao......Wishing you the biggest birthday celebration today, good health and more flashlights to build. 

lg.tech
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Happy Birthday Simon!
Have a great day, cheers!

raccoon city
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Happy Birthday, Simon!  ^:)

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Happy birthday Simon! Thanks for your continued interaction with us. It is greatly appreciated.

Tatteredmidnight
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tactical_grizzly wrote:
Tatteredmidnight wrote:
BlueSwordM wrote:
Or better yet, just use higher power cells like the Samsung 30Q or Molicel P28A.

The NCR18650GA is a 5-8A cell at best honestly, and going at 10A isn’t the best idea to get out most capacity out a high power LED.

As someone mentioned above, at 18A, it should be pulling about 4.5A per cell, which may cause sag in an NCR18650GA, but should be well within its capabilities. Probably less at most voltages since it’s a buck converter and the vF is close to 3v, so at higher cell voltages, it should be pulling less than 4.5A for the driver to deliver 18A @ 3v.

4×18A’s driver is linear, not buck

Also, max achievable turbo brightness drops smoothly as the batteries drain so it makes sense that voltage sag is the cause.

I didn’t know the regulator was linear, touché. Still, worst case is 4 – 6A draw per cell. Voltage sag may still be the culprit, but well within the cells’ capabilities. Only way to know for sure would be to test with different cells and compare I suppose.

thefreeman
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About 70~80mV higher with 30Q at 5A at high SOC, not a big difference but it can help a bit.
More importantly the 180mV drop across the sense resistor doesn’t help.

With 30Qs and a more reasonable 50mV Vsense, 0.2V would be saved, that’s significant.

Simon Mao
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Alen wrote:
Simon,

I want see which of these drivers is less bright.
Can you post a photo comparison between the13 group driver powered by Ni-Mh AA batt.

https://aliexpress.com/item/1005003374477862.html

and the 4×7135 new firmware driver powered by lithium?

https://aliexpress.com/item/32734523412.html

Both drivers set at minimum level brightness with same Led type

Thanks

7135*4 is out of stock

Simon Mao
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Superstocker wrote:
Happy birthday Simon! Thanks for your continued interaction with us. It is greatly appreciated.
raccoon city wrote:

Happy Birthday, Simon!  ^:)


lg.tech wrote:
Happy Birthday Simon!
Have a great day, cheers!

Chinaheart wrote:

Happy Birthday Simon Mao……Wishing you the biggest birthday celebration today, good health and more flashlights to build. 

Although today is not my birthday, I still want to thank you all. Party
There’s an interesting thing in there. China has a lunar calendar and a solar calendar. Actually my birthday is counted according to the lunar calendar. Big Smile

NeutralFan
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When will the 23.2*1.4mm ar-coated glass lens ,suitable for Convoy S21A S21B be available with the new green AR coating?

I’d rather use my flashlight around the house than turn on the lights.

Simon Mao
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NeutralFan wrote:
When will the 23.2*1.4mm ar-coated glass lens ,suitable for Convoy S21A S21B be available with the new green AR coating?

Some use new green coated lenses.

NeutralFan
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Simon Mao wrote:
NeutralFan wrote:
When will the 23.2*1.4mm ar-coated glass lens ,suitable for Convoy S21A S21B be available with the new green AR coating?

Some use new green coated lenses.

Excellent, I’ll add the lens to my order!

I’d rather use my flashlight around the house than turn on the lights.

primarycolorsnomore
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Simon, is there any chance of adding additional colors to the standard anodized aluminum S2+? It would be great to see a yellow one.

Simon Mao
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primarycolorsnomore wrote:
Simon, is there any chance of adding additional colors to the standard anodized aluminum S2+? It would be great to see a yellow one.

Yellow doesn’t look very flattering
Simon Mao
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Titanium alloy T4

primarycolorsnomore
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Simon Mao wrote:
primarycolorsnomore wrote:
Simon, is there any chance of adding additional colors to the standard anodized aluminum S2+? It would be great to see a yellow one.
Yellow doesn’t look very flattering

Hey that’s my favorite color! Wink

I understand though if it’s not worth it to manufacture since there wont be enough demand.

Do you have an estimate of when the MAO version will be available?

trakcon
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Simon Mao wrote:
Titanium alloy T4

Wow. That’s gorgeous! What else is coming in Ti?

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