Modifying a Milwaukee M18, need suggestions on parts (led, driver, etc)

sactime

Newly Enlightened
Joined
Dec 13, 2007
Messages
31
Hello,

It's been a long while since I've modified a flashlight and I'm out of date with current tech (last I knew the P7 was the LED to have).

My Milwaukee M18 led light is pretty sad and puts out minimal light. I'd like to upgrade the led and need suggestions on which LED and driver to use (18v input). Ideally I think it will come down to heat and efficiency since I'd like to be able to run this light for at least 30 minutes without worry of overheating. I think I'd like to stick with single mode, but am open to the idea of two mode (low and high).

I attached some photos of the Milwaukee taken apart.

Is 1000 lumens possible without major upgrades to the heatsink? Thanks!
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LEDphile

Enlightened
Joined
Mar 8, 2021
Messages
215
Unless that head is metal, you're likely already thermally limited. That LED looks like one of the "high efficiency" packages from Cree (XT-E or XP-G families), and should be good for north of 400 lumens out of the package. Milwaukee, on the other hand, rates their unit for 100 lumens, suggesting they are not driving at max current. Given that a 3AH pack should be good for 8+ hours of operation at a 2A LED drive (max for XP-G family), there's almost certainly some other reason for the low lumen output. My guess is thermal, given that there doesn't look to be much heatsink in that head.

But if you do want to try driving the LED harder and don't mind stressing components, I'm guessing you should be able to modify the current-set resistor on the driver for higher current with only minimal work (once you have determined which part on the driver board that is, of course).
 

sactime

Newly Enlightened
Joined
Dec 13, 2007
Messages
31
The head is aluminum. I attached a photo of the area behind where the led is mounted.

I'll be honest I do not know enough about how to modify the resistor on the current driver. It might be easier for me to get a compatible led and driver and wire them together.

Thanks!
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turbodog

Flashaholic
Joined
Jun 23, 2003
Messages
6,006
Location
Southern USA
Looks to be plenty of room to add a small 1" fan and pull air through the head. Drill a hole and add a 2nd switch to activate.
 
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