[Modding] Astrolux MF01 --> OSH park NarsilM

So I have an MF01 and was considering this. Is the brass driver ring that the battery tube contacts soldered to the stock driver? If so how did you remove it?

What settings did you choose for your driver?

the current is divided through 9 emitters 2 in series
so about 2.5A per LED

you have per emitter a relative low current compared to single LED builds

even if most people does not believe it if the LED stays cool a higher current it ages less than on normal current
and on low modes it ages a lot faster than on normal current
so moonlight is a real lifetime killer for LEDs

This is also why you often find minimum current requirements in datasheets to get to the right lifetime

LEDs age a lot faster on low currents? Any link/reference that supports this funny statement?

It is physics, the current protects the active zone from degradation

Watch this video

The picture before it plays shows the aging with current, the solid line shows longer life for 350mA, while the other for 100mA shows less for the same LED temperature, a DTP star keeps the LED a lot cooler than conventional cheap aluminum stars that are used in most application to save costs

There are tests that clearly show that if the LED keeps cool enough on the LED die a higher current makes in fact the LED age less than on lower current
LED ages from a process that is mainly rapidly increased at low currents like moonlight or low the LED can age 10 times faster than on full current

I watched this video multiple times

And I am native german, so I did understand well why low currents are far worse than heat to kill LEDs

The current protects the very thin active light emitting zone from electrically defective spots to migrate into it from the surrounding material, this active zone is a lot thinner than the rest so migration is a huge issue
Of course heat also increases the migration of electrically defective spots

On our CC moonlight flashlight the LED can age over 10 times faster than on max. rated current
You see the plot at 16:00 of the video
And that plot shows the LED running on 3% of its normal current
Our moonlights and firefliey modes on CC lights get below 0.1%

The odd thing is if we get good cooling an overdriven LED ages slower than at rated current when they got the same junction temperature

Ok, so what about PWM modes? if we have 1A with 0,1% duty cycle, will it cause LED to degrade 10 times faster as well?…

Pwm modes at LED nominal currents will be fine for lifetime
For XPL this means 0.35-3A on a cheap star if the junction stays within specification temperature limit

Basically the cooler it runs and the more current it gets the less it ages

Following

thanks lexel for the details. interesting indeed ! i wouldnt imagine that behavoir for low current. physics are not always obvious

Thanks for the video, I'll check it later, but I can say immediately something is wrong in "less current - less lifetime" logic,

if this is correct then worst case for LED lifetime is not to turn LED at all (leave it in reel for 1 year).

If 10x lifetime decrease at very low currents (0mA must be the worst by this logic) is true, then completely new,never used LED 1 year after production would be at the end of its life (1 year is ~8000hrs, 10x is ~80000hrs).

Your claim that "more current - less ageing" is completely wrong, you can check some L70 tests for various LEDs, at same Tj, LED at higher current ages faster.

This picture summarizes temperature and current effect on LED lifetime(btw check LED lumen output at 350mA - no drop at all after 100000 hrs):

In the Osram video they talk about a 350mA LED
At 100mA and 150dC it ages slower than on 10mA with 55dC, if you compare both pictures

So why do have Luxeon LEDs the opposite lifetime correlation?

Likely because at some point another factor comes in play.
Maybe thermal stress, who knows

In any case if you cool the LED better the lifetime gets rapidly better as well.

At very low currents the LED gets damaged by diffusion of defective spots in the active zone.

At zero current or close there is not enough energy present to move defective spots.

Even if he drives a XHP70 at 6V 7.2A with a DTP star he gets thousands hours to 70% brightness
If he drives a XHP70 at 50mA it will age probably as fast as with 7.2A

In flashlight use noone will probably see a significant degradation of brightness with a lot normal use

Nice! I’ve been on the fence about this mod ever since I noticed that one bank of leds is a tiny bit dimmer than the other two when in low mode.

It looks quite do-able and I love ramping on my other lights (Q8 and D4).

Any challenges or bumps in the road to look out for? How was it taking off the bezel to get at the emitters? Wasn’t there a warning from Astrolux about removing the bezel and damaging the leds?

So in other words making a moonlight with very low duty cycle PWM should increase LED life while the same moonlight with constant current will make it wear much more rapidly (altough with little more lumens per watt)…
I wonder if 20+ kHz range PWM can have any negative effect on LED though…

PWM increases the LED life in 2 ways the low current age is a lot less plus the LED is only 1/100 of the time on
so that would increase the lifetime by a couple hundred times at least

new version of MF01 needs to get a MCPCB modification as well

you can ignore the cables I put in there, basically you can wire it like you want, just make sure the red circles and the black circles are connected towards each other

the cables of me are in the 3 120° sections just different approaches

you cut so that 2 LEDs are together in series, while to board had originally 6 in series, so 2 cuts per 120° section

Wouaaa just 2 small wires. The current is lower?? What the new configuration? Old was 2S3P right?

new uses a boost driver to 20V LED voltage

Are you sure about this? Doesn’t this also mean that the new version with boost driver is able to maintain turbo output with depleting cells?

absolutely sure its 6S on the output of the driver

It wont be able to deliver Turbo much longer, the light pulls 120W from the cells and at like 30% discharge of the cells, it will fall out of Max brightness
The 2S driver can go to DD if the Buck regulator falls out of regulation while the boost driver gets more and more inefficient with dropping cell voltage and higher input current

Thanks! Freeme confirmed this as well. Really interesting development here. Ok I understand less cell voltage means more current is required for 120W with boost driver. But how how do you know the figures that with 30% discharge it will fall out of max brightness? Secondly, how many lumens would you loose? Just 5, or 25? Isn’t an actual test required to know these values?
I do know from my own ceiling bounce test using the M43 as a reference that with 3.75V for the 30Q in the MF01, I get less output (about 6000 lumens) than my M43. I’m curious then how many lumens the new boost driven MF01 will pump out… Output as a function of cell voltage is what I’m after.

This depends mainly how efficient the driver can boost without getting saturation in the inductors or other hardware limitations