75W MR-16 M*g Mod FAQ?

[Action]

Can anyone point me to threads that cover the gamut of MR-16 mods (not LED), particularly mods with a 75W MR-16 or greater? I can pull up Ginseng's posts in the archives, but pics are missing and most discussion is around the 50W or less versions...

I'm particularly interested in hearing from someone that has done a 75W MR-16 with Lions and NiMH cells. I also want to hear is there are switch issues with the stock Mag switch at these power levels. Any suggestions or guidance would be very welcome. An optimal build for me would be an overdriven 75W MR-16 with 20-30 minutes of runtime, is such a beast possible in a 4D or smaller size?

 

[bwaites]

Action, You might get 20 minutes, but that stretches it a lot, 30 is probably out of the question.

Two issues crop up, first batteries to run it for that long, second, heat.

Running a 75 watt lamp in a Mag body creates a lot of heat, and the body absorbs that heat. The light gets so hot that it becomes impossible to hold.

Most 75 watt lamps pull 5-6 amps. That gives you about 12-15 minutes tops, using multiple AA cells. Using LiIon cells, the only cells that will let you do that are unprotected cells, and that's greater than 2c on the better 18650 cells, so you are into the high risk light area.

You can do it in a 3D body, that's what Ginseng's Polaris project was built in. I've had no problems running the stock switch in similar lights, as long as you make the appropriate low resistance mods discussed at great length here in other threads.

Bill

 

[mdocod]

Here's what I have learned about most MR-16s...

they are halogen lamps rated for 12V, but designed to last for anywhere from 2000-6000 hours at 12V...

at 12V, these lamps are not very exciting, but they have a lot of room for improvement if you can come up with a higher voltage power source. I have run Philips 20W MR-16s direct drive on 14NIMH AAs (so probably approaching 17V under a load fresh off the charger)... and there was still probably plenty of room to go another cell or 2 in the circuit before instaPOOF.....

Most mag mods are using lamps that get more exciting at a lower voltage, because putting more and more cells in series to get the voltage up complicates things and adds more possible points of resistance..

if you want a 75W mag-mod.... use a 50W MR-16, and drive it to around 18V, it'll actually be in the ballpark of 80+W at that voltage, and very nice and white. (way more efficient too).... These long life halogens are usually only making about 10LM/W at the 12V they are rated for... push them up to around 16-20V and you start getting more like 25LM/W..... You may need to experiment with some various MR-16s... the ones rated for lower life might actually be better for overdriving because you won't have to come up with as high a voltage to make them scream.... The ones rated for 6000 hours will likely need in the ballpark of 22V before they get really exciting.. YMMV ..... it's been awhile since I've played with these..

 

[mdocod]

I think a good, safe, easy solution..... giving the right bulb would be as follows:

a 5C maglight.
5 of AWs up and coming C size LI-ION cells. (protected).
a 50W MR-16 rated for at least 4000 hours at 12V.

this should result in a current draw of somewhere around 4.3-4.6 amps, which those cells can deliver without a hitch, runtime will be about 45 minuts, brightness should be around 2000 lumens.

 

[bwaites]

Actually, at 15 volts, you will draw closer to 5-5.5 amps, and the cells at that draw rate will only be good for around 2.3AH, so you'll get less than 30 minutes out of them. (I had to do those calcultations in my head, so they'll be off a little bit I'm sure).

My experience with 18650 cells, mostly LG cells, seems to show that for every 1C over 1C you go, you lose about 30-40% of the capacity, so AW cells, at least these prototypes, seem to do better.

Bill

 

[Action]

I knew that I could count on someone knowing the skinny on these bulbs.

Just what is instaflash territory with these bulbs? If you were looking to produce a 15-20 minute 75W MR-16, what would you build/use? What if I reduced it down to a 15-20 minute 50W MR-16? What would you think of using the pack listed here to power an MR-16 (albeit in a 2D body).
http://candlepowerforums.com/vb/showthread.php?t=106953

I guess that what I'm looking at is:

1. How to build a relatively hot MR-16 setup with minimal effort (no switch mods, cutting tubes). Batteries choice is open, as is holder choice, and we assume boro lens with Kiu socket.

2. If one were to go to more effort (modded switches and cutdown tubes with hotdrivers etc) what would be your suggestion for a really hot MR-16 setup?

 

[LEDcandle]

I feel like I'm advertising my mod here with the recent questions on hotwire mags but here is prob the 'hottest' MR-16 format you can do :-
http://www.candlepowerforums.com/vb/showthread.php?t=110551&highlight=magddl

150w, 20v DDL bulb. No lumen numbers from manufacturer but estimated at least 5-6k. 500hr life (room to overdrive), and not 25-50 like some of the highest end Osram 100w bulbs.

For a 75w or 100w based on 12v platform, a 'simple' Modamag 12AA to 3D batt holder (dunno if he's still selling them? this is the old thread I bought from :- http://candlepowerforums.com/vb/showthread.php?t=96929&highlight=holder) should power it just fine. Using 2700mah Sanyo batts in series, you'll get about 14.4v under load which will overdrive the bulb but no problem since these 50-75w have 2000-4000 hrs life. Current will be 4-5A, no problems for the Sanyos (around 2C or less).

Runtime, 25-30 mins of diminishing brightness. Of course, getting the kiu socket done up is not really considered 'simple'.. (well in that I mean its not a bolt-on), but if you you can handle that, then the rest is simple.

I have a 3D Mag MR-16 platform which I can swap to 20w, 50w, 75w or 100w as I like as they are all 12v. (Not the MagDDL which is a separate 4D mag)

Install Kiu socket, plug in your MR16, load up the batts in holder and it should work. Please do take note though, that fitting 4 batts across in a stock mag might be tricky. Not sure about the 2700s, but here is a tutorial on the 2500s...
http://www.candlepowerforums.com/vb/showthread.php?t=107772&highlight=sanyo

I've personally tried it and it works!

So the long and short of it, a 12v in a 3Dmag platform is pretty easy. There are also D-sized Li-ons in the works, and 3 of those would give you your 12v. If you are going the NiMh way, do the 12AA to 3D as I mentioned for 14.4v. (add dummy batt if you want a lower voltage)

Just remember for an MR-16 mag, install the head first without the bezel ring and lens, then plug your MR-16 in. Screw back on the ring/lens.

When opening it up, don't unscrew the entire head by mistake; you'll most probably twist the leads of the MR-16! Unscrew the bezel ring first, then pry out your MR-16, THEN unscrew the head.

Good luck with your mod!

 

[mdocod]

it was a long time ago that I was playing around with some of these various lamps... As I recall, one lamp that I was playing with was a 50W GE-Edison.... I've since been using one as a reverse/utility light (mounted in some PVC pieces) screwed onto the rear bumper of my isuzu... wired to a toggle switch on the dash... I can't remember who it was I was chatting with on the board.... but someone mentioned being able to drive one of these lamps on 2 12V SLAs in series and it still didn't blow... suggesting that the bulb survived somewhere in the ballpark of 22V (under the load), possibly more.... SLA can deliver a lot of current without complaint.. (I've pulled over 30 amps out of a 7AH SLA, doesn't last long, but it continues to charge up and work without any major issues)...

I personally don't think 14.4V is what you want to shoot for.. at that voltage, the lamp will still be pretty yellow... Like I said before, I've run some 20W philips MR-16 halogens on 12 NIMH, and also on 14NIMH... even on 14, it still wasn't all that white... there's definitely more overdrive potential in these lamps..

 

[LEDcandle]

Yup, they definitely can be overdriven quite a bit but to maintain a portable size, I think the Mag 3D is a great platform. 14.4v is a pretty decent overdrive for that size; at least its not underdriving the light and wasting its potential.

A 50w spews about 1300 lumens or so; pretty good already considering the SF M6 is about 800 lumens actual and very useful as it is. I'm not sure if the original poster is looking for the whitest output possible, but for me the output is nice and warm and not too yellow. Definitely very usable.

Personally, I think the 2 or 3 cell Mags are about as long as you should go for a nice balanced feel in hand. Of course longer maglites can be balanced if held in the center as well, but then your thumb isn't positioned at the switch. The 3D is a nice size.

 

[Action]

Just thinking about the comments on overdriving the bulbs increasing the efficiency and improving the color...

What if I wanted to go with 9x14500 Lion cells in one of FM's NiMH AA battery holders. This should be able to give around 37V resting with very limited current.

Or if current was the limiting factor, I could use one of the 9x14500 Lion holders to deliver just over 16.6V resting with much greater current.

Another option would be a serial/parallel setup in a quad bore Mag 4X3 for just over 25V and a medium current capacity.

I would only use AW's protected cells in something like this.

I guess that the best NiMH solution would be a 4X3 setup in a quad bore Mag. If I were to use Sanyos only and did not want to damage them, what would be my limit in terms of the bulb wattage?

 

[bwaites]

Action,

Unless you want to have something in your hand explode, running 14500's at the current draw these are capable of is a little crazy.

14500 in series are good for about 2C, 3C at the most, so you are talking 2-3 amps, maybe a tiny bit more. 2C is reasonably safe, 3C is pretty much pushing it to the very edge, above that, you are crazy!

4x3 Sanyos will sustain 5-6 amps, but they are really straining at that.

Check out these threads for more on batteries:

http://www.candlepowerforums.com/vb/showthread.php?t=79302

and

http://www.candlepowerforums.com/vb/showthread.php?t=117117

and

http://www.candlepowerforums.com/vb/showthread.php?t=53985&highlight=CPF+University

 

[Action]

I know that Lion has extremely limited current capacity. Running a 50W bulb on them is not a happening thing, I just really like their low discharge, high voltage and light weight.

OK, now that I've got my Lion lovin' off my chest, what battery setups would you recommend to power a really nice MR-16 setup? I know about the 4X3 setups for AA are tight and often require quad boring and 3x3 setups in AA fit in stock tubes, the 4X3 looks to be the best of the readily available setups. However given some of the work done with 4/5A GP2000 cells by andrewwynn, wouldn't these be a much better choice as a tri bore in a really bright MR-16? Given the voltage that the MR-16 could take, it would not need a hotdriver or anything. A question would be if a stock switch would hold up...

 

[LEDcandle]

If you have to go with Li-ons, then wait for the Li-on D cells to come. At 5200 mah, they can handle 10A without much problem.

Of course using high current cells like the GP and CBP will result in a much nicer runtime curve and less stress on the batteries. If you want to send the light for tri-boring, no harm using those 4/5As. If you don't want to mess with that, the 12AAs to 3D should work for you and if nothing else changed, it should fit in an unbored mag 4 across like I posted.

The stock switch on my Mag50w has no issues. The switch on my 150w gets 'sticky' as I was saying on another thread. You know how high current causes things to stick... well, it happens to the switch. Sometimes, it takes a couple of presses to get the light to switch off. Current is about 7A. Not sure if the switch is starting to melt or anything because I've never opened it up to see (not conveniently accessible short of disassembling the whole thing again).

 

[Action]

I've been checking the Li-on D cell thread fairly often. Things aren't looking so good for them in the next few months at least.

I was thinking that with the 4/5As that they could actually run a 75W MR-16 without harming the cells and should be plenty bright. If the battery back was a 4x3 it would overvolt to ~14.4V. It should even be able to run a 100W MR-16 without a problem, except the switch issue.

 

[mdocod]

Like I said... your easiest solution, that will be doable within a few weeks... is a 4 or 5 C size maglight... and AWs new C cells(should be available before the end of the month)... I'm pretty sure they will be able to fire up a 50W bulb no problem... current shouldn't be any more than 6 amps, like said before... probably closer to 5 amps... which would give you around 30 minuts runtime, a lot less cells to deal with, no boring out bodies, no battery carriers full of contacts. basically, a lot less hassle... Waiting for the D cells might be good too... I haven't followed that thread as closely, so I'm not sure if they carry all the protection and build quality that you will get from AW.. 5 C Li-Ion will give you 21V fresh off the charger... at 5 amps, that should drop to about 19V or so.. perfect territory to make these MR-16s beautiful... and if you instaflash one, you always have lots of other brands available to try out... Would be nice to be able to swap in a 35W bulb when you want more runtime, and quickly swap to a 50W when you want more light... you could have a collection of various beam shapes too!!! MR-16s sure are fun!!

 

[02Scuba]

Driving an MR-16 at 14.4 volts is more than enough to get a nice white beam from. The trick in my experience is to use the right MR-16. So-Lux puts out a line of MR-16s that are designend to run at 5000 - 6300K at 12 volts. Overdrive the So-Lux 50 watte MR-16 by 25% (or 14.4 volts) and you get a really nice white light at about a 1000 lumens. The So-Lux lights come in 12 degree spot and flood variations and in 20, 35 and 50 watt variations.

Until I switched to a 24 watt Darkbuster HID dive light (and now to a Polarion) I used the 12 volt 50 watt So-Lux overdriven to 14.4 volts as my primary dive light. I would still be using it but for the fact that it started to dim after about 40 minutes and I would have to shut it down or risk damaging the Ni-mi battery back.

The Darkbuster is brighter and has a 135 minute run time but the MR-!6 So-Lux at 14.4 volt puts out more light than 95%of the other dive lights I see on the dive boats I'm on. Try it !

 

[mdocod]

I've looked at those Solux bulbs, and thought about playing with them, but I just can't get myself to order one... we all know that a tungsten will basically evaporate once you try to achieve anything higher than about 3600K output temp. They are claiming numbers that no incandecent bulb I've ever heard about could do. So either they use filters to change the peak output temp (reducing overall output) or they are flat out lying...

 

[DFiorentino]

So either they use filters to change the peak output temp (reducing overall output)

Bingo.

I've tried them and while pleasing to the eye, there are very inefficient lumen-wise. This is why I use Phillips 45W IRC MR-16 in my work Mag. Yellowish...yes, but nice and bright for the power applied. Oh, DD off 12AA.

-DF