3D-Mag LED help plz

[LupusLynx]

Hey guys and girls,

I would like to upgrade my 3D Mag with an LED and probably a Step-up-converter as i guess the 4.5 and less Volts won't be enough to run it very well..?
Does someone have the shematics for a nice circuit I can use?
I'd like to run it as a back up Flashlight if I only have batteries and can't recharge the rechargeable batteries of my main FL.
So something like a two stage 200&800lm maybe?
Plz feel free to answer with whatever you think might be useful.

Thenkfully yours, LL!

 

[LilKevin715]

I'd like to run it as a back up Flashlight if I only have batteries and can't recharge the rechargeable batteries of my main FL.

It sounds like you only want to run Alkaline cells? If thats the case they won't perform very well. Most alkaline D cells can't sustain much more than 1 amp current draw, and not for very long either. You would probably be better off getting a dropin from Terralux or Malkoff if you are going to run Alkaline cells.

 

[yazovyet]

Depends on what level of work you want to do. Often people might buy a driver that regulates current (and maybe boosts or reduces voltage). Commonly LEDs will tend to use around 3 or a little more volts. Thus a common mod is based on the "amc 7135", check those mods out and see if that's the level of work you're looking for.

But the problem (as was stated above) is that alkilines (even D cells) can't put out very much power and if you do make them do it their run time will be SHORT. 3 alkalines discharging at 3 amps would get you around that 800 lm (real) mark when new but the voltage sags down under such high load very fast, like 5 to 10 min and you're below the 1.1v (or more) needed per cell. The 5,6,7th graphs are for D cells and show their run times at different discharge rates. http://www.candlepowerforums.com/vb/showthread.php?64660-Alkaline-Battery-Shoot-Out At 1 amp you might get 2 hours runtime and around 200-250 lm (real lumens, maybe 300-350 emitter lumens).

The drop in route could have similar run characteristics as getting components yourself and putting it all together and I don't know what a drop in costs or too much about which one you'd want. Buying and assembeling components could cost something like 20 for the heatsink, 5 for the driver, and maybe 5-10 LED. For a total of not less than 35 and quit likely more you'd have a light that eats alkilines and isn't terribly bright. The plus side would be that you could also run 3x NiMH in this light if you wanted but at that point you might as well decide to make a NiMH light (I'm sure you can look up others who have done that here. hint: kevin's signature). AND if you were able to get 2 Lithium ion cells in parallel in it they would work too; and assuming they were decent sized, give good run times and light. But with the lithiums you're into another 35+ for batteries and charger and a little more for rigging them in parallel and you have basically made a new powerful flashlight instead of making a back up. So do you want to undertake a project that has a totally different goal from the one you were thinking of just because you have a host body for a flashlight?

TL;RD: It isn't worth spending money modifying a flashlight to run alkalines.

What is your current flashlight and batteries that you mentioned?

 

[Tmad]

Personally, I'd just do it direct drive (no driver). That' what I do when do an akaline build. Get a heat sink (H22A) in the b/s/t, and wire it up

 

[alpg88]

yea, i agree, DD should work, even with no driver, fresh cells are not able to supply enough to damage led anyway. but i would use simple linear 8xamc 7135 board, at least you'll be able to change modes.

 

[HarryN]

I am in the process of making AA based battery packs for my D cell lights. In most cases, you can figure out a way to make 3 AAs take up the same space as a D cell, and use energizer Li primary cells for those times when a light needs to just sit around for a long time, and then just work.

There are adapters on the market, but I am playing with other ways to build up the pack, some of them are pretty crude and simple based on tape. It is a work in progress, and I am just using some cheap AAs to mock things up so far.

 

[pyro1son]

I can't for the life of me remember where but I saw a Maglite mod not too long ago where it was a XM-L on H22A heatsink with 7135 driver and powered by 3 standard D cells. Really simple and should work well!