Hi vieplis, did you really measure 1A WITH 2.5ohm resistor? That would mean a Vf of exactly 12V.
I read from other thread mentioning a 1.3A pull from 11.8V battery, meaning it's Vf is actually somewhat lower.
The problem with flashlight control modules is in the reliable factor. The Buckdrive is a 24/7/365 device that can take shock and variable voltage that your mower genarator/alternator will produce. Running two XM-L emitters in series @ 2.1A should produce adequate lightning with minimal heatsink issues. Read the pdf file for more info. I have used this controller on my 12 volt 48 watt solar panel hog light setup that runs two 3up XR-C (6 leds total) every night for over the last year.
This single mode driver will deliver about 2.5 amps to an XML from a 12 volt supply. They are super cheap and that’s about 800 lumen which wills seam extremely bright compared to an incandescent. Just solder some long leads onto it and glue it with Fujik into the housing.
Thanks for the responses. Thanks for that link Erik! Any suggestions on using a reflector or not? If so, what? I'm looking for floody light, so should I use a P60 OP reflector? Remember, this is behind the current headlight plastic lens.
-Garry
plenty of cheap HID kits on Ebay
If I do end up doing this build, I'll be sure to post before and after "beamshots"! I intend on snipping the 12 volt leads in such a way that I can always splice the old bulb holders back in place should I have a need to.
By the way, last season I replaced the stock bulbs with these PIAA 27 watt Xtreme white ones. They did make quite a difference, but I'm looking for a lot more light! It's still so darn hard to see anything right at dusk!
-Garry
EDIT - Added missing link.
For a "reflector", how about using these 60 degree optics from I.O.S.? (Seems I.O.S. keeps adding a lot of nice products, especially the "D.I.Y." products). I want the larger angle optics for a wider beam, right?
My other option would be a C8 reflector with these wide angle lenses (of which I have one). Problem there is how to mount them.
Thoughts?
-Garry
what I’d do is:
run 3 XM-L in series at 1A (or 1.5A max), bolt them onto the biggest CPU heatsink you can find and use 20mm elliptical optics. That’ll get you 7-900lm OTF and give you a manageable 10W of heat to dissipate within the confines of the existing headlight. The ellipticals should give you a wide beam that throws far enough for you to avoid the dog/ garden gnome/ etc but without wasting a whole load of light by throwing it up into the sky.
I’d go with a single mode driver and wire it into the existing switch set up. Buy several and rubber mount it where it’s easy to replace if a voltage spike kills it 
What i did was also from automitive batt (dunno if it make sense for your case).
Previously, i use car batt, wire out to my flashlight (tf-3t6) to be use as floody light for house in plantation. So far over 20 time, each time bout 9hours run.
**Buy a flashlight, remove the head (drivers+xml intact), connect + and - into it…
(Of course i do not know if that will be bang for buck in your case, i do it cos i do the easiest way w/o buying seperate & hv to solder them back)
Or, if u feel u need some light that shine towards your back, you can also direct run 12v wires to power SD 01 - 12v MR16 3w led (same as the light posted by dchomak), its only 270 lumen ber bulb. i am also powering 10 piece of them using 12v car batt only, no alternator, each run 10 hours, quite ok.
Hope it helps…
Could you just bike mout and wire too the dropin and body with a toggle switch where the tailcap was? Or drill a whole in the body and run the negative to the tailcap and positive to the dropin spring? Would the tailcap handle the amps?
Sorry to go way off topic, but that looks like a cheap and cheery maglite mod waiting to happen. Could you measure the diameter of the heatsink at its widest, and the depth of the heatsink and that plate together?
Thanks in advance!
50mm x 23mm
To measure I went over to my spare parts box and a there is a Mag reflector and this light sitting right next to each other!
Here is another, cheaper option
Thanks, dchomak! Worst case, the mag head needs a little trim at the bottom, it seems.
I’ve been staring at one of OldLumens’ 1d beauties for the last couple of days, and one of those might be just the thing. (Not that I’m too cheap to buy a ‘proper’ heatsink or nothing, but this is the land of budget, right? And if we’re going for full disclosure, it does hurt just a little to think about spending $15 on a spun hunk of aluminum.)
How would you drive one of those in a Mag? What driver and how many cells?
-Garry
Garry Here's some USA based components. Just some ideas for you.
CPU Fan/Heat Sink or this one, less money
I can't find a driver right off hand. Only in China
http://kaidomain.com/product/details.S020079
http://kaidomain.com/product/details.S020148
The heatsink is only an example, there's lots of CPU heatsinks with 12v fans on them, for less money.
IMO, this is by far the best and most obvious solution. DX and many others have them as well. Dirt cheap, mega-lumens per watt, huge choice of tints and wattage, variable voltage tolerant, vibration resistant and simple installation. How many amps is your alternator rated for?
Buy a couple of the cheapest 10W Chinese wall wash floodlights that you can find (say $10-$15) and mount your LEDs and drivers in them. The housings are really nice for these sorts of things.
BTW, E1320’s Kaidomain driver link says it is only 1A…
Automotive supplies are notoriously ‘noisy’, full of voltage spikes that can fry electronic components. Im not sure exactly, but I think that a Transient Voltage Suppressor between the mower and led driver circuit will help protect.
Im sure the more electronic savvy members will be able help with this, maybe….
Woody
I have no idea. I wanted to stay under what the stock bulbs were pulling. Now I can't remember what stock wattage was, but I am using (2) 27 watt bulbs now. So that's roughly 54 watts/12volts = 4.5A. Right?
That's an idea that came about after this thread was posted and I already purchased the KD drivers, emitters, and optics. Have done nothing with them yet, but I have them! :) Maybe some day! I even thought about those chinese MR16 LED bulbs as-is (highest rated output I can find), but I don't think they'd be bright enough.
I do need to take a closer look at the voltage being fed to the current bulbs and do some monitoring.
-Garry