Convert 6 volt Lantern to LED?

Hello everyone! First post here. Just getting into high power LED flashlights and interested in getting started with a few D.I.Y. mods. I have a Rayovac 6volt Lantern (the cheapie plastic floating lantern that utilizes those large 6 volt lantern batteries. I'd like some ideas to mod it to an LED floodlight. I'd like to have it "flood" a large area with light at the expense of throw. It doesn't have to be insanely bright, just a nice useful amount of light and a good long runtime (at least 4 hours) and run cool enough to be on continuously for 1 hour+. I'd like to stick to the simple 6volt lantern battery, but would consider converting to some sort of other battery pack.

I do understand the lantern is center negative, and I believe this could be addressed during the mod.

What kind of limitations (amperage or voltage) would I run into using the lantern battery? Could it run an XML (albeit at lower than max output)? Or is there a better option? How about the Fusion 36? Although reviews seem to indicate those don't last long. What is a good "efficient" emitter that puts out enough light with wide "spill" for flood use? How about this 5xCree R2 drop-in from DX http://www.dealextreme.com/p/5-cree-r2-5-mode-1200-lumen-white-light-drop-in-led-module-52-7mm-42mm-8-4v-max-35242 ? Would this draw too much current? What kind of runtime might I expect?

I've got lots of other questions for other categories being a newbie, but I'll start with this post.

Thanks for the help!

Garry

Well, I stopped by Lowes last night and swung by the flashlights. I saw that they have an 80 Lumen lantern (same design as the typical "6V" lanterns, but I can't remember if it runs on the big 6volt battery or not - online lists it running on "3 batteries"). I think it was rated 16 hours, but not quite sure and online lists few specs and no reviews. It's found here: http://www.lowes.com/pd_352085-50584-FT-IN-6VTZ_0__?productId=3408530&Ntt=flashlight&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dflashlight%26page%3D1&facetInfo= .

Curious what the spill of this light is like.

Garry

"It doesn't have to be insanely bright, just a nice useful amount of light and a good long runtime (at least 4 hours) and run cool enough to be on continuously for 1 hour+. I'd like to stick to the simple 6volt lantern battery, but would consider converting to some sort of other battery pack."

6V batteries are 4x1.5V batteries in fact.

I haven't used this type of battery. They are alkaline batteries. Are you aware of the resistance of the alkalines to high currents?
There are many issues there, how are you going to mount a LED, plastic body means no heatsinking.
Are you familiar with the forward voltage of the LEDs?

"How about this 5xCree R2 drop-in from DX http://www.dealextreme.com/p/5-cree-r2-5-mode-1200-lumen-white-light-drop-in-led-module-52-7mm-42mm-8-4v-max-35242 ? "

That will get you the exact opposite of the flood.

You should read the forum, there's a lot of information here. Maybe you should start by buying a LED flashlight. See how's the output, lumens, runtimes, heat, throw, spill. See what you like or what you don't like.

Welcome to BLF garry!

I did have the same thinking as you when i saw this lantern at Lowes for $3.99. BUt hikelite is right, the body doesn't have heatsinking since plastic doesn't conduct heat and the high current LED might melt it.

I am trying to read up on LED's and get enough of an understanding. I was hoping to be able to throw an LED drop-in into this type of Lantern which would already have enough heatsinking on it. I understand heatsinking to be an issue with the plastic body. I'm not asking for 1200 Lumen output really, just enough flood of light. Based on LED lights I own, I'd say somewhere around 150 Lumen would be the starting point.

Any thoughts on throwing the Fusion 36 into one of these? I know the reflector would need hacked.

Garry

I have just that sort of 6V light from ACE Hardware, it has a very useful, adjustable stand built in that make it great for working around the house. A while back, after modding most of my Mags I had all those stock Mag bulbs kicking around so I thought I'd throw the 4D bulb into the ACE light to see what I ended up with. When I took a better look at the ACE socket I realized it was center +. I grabbed a TerraLux MiniStar1 and installed it and was quite impressed. The MiniStar is only 1 watt rated at 50 lumens but with the big reflector the light really throws with a nice clean center spot and good spill. I've test fitted a TerraLux TLE-6EX (3 watts at 140 lumen) into the socket but that was just to see if I could, I'm afraid I'll melt the socket and reflector. I use this light all the time around the house because it's so easy to get the light where I need it and the run time is off the chart. I plan on adding some diffuser film to better suit my needs.

If I find another of the same lights I'll give the TLE-6EX a try. Unless you can find an old 6V lantern like I had when I was a kid (everything was metal back then), it think your limited in lumens.

Well my stock rayovac light is rated 75 lumens (and 4.5 hours runtime). I was thinking of a 3 watt LED drop in at least, but didn't think the 3 watt would cause that much heat. Could always remove the plastic lens!

Yeah, I saw a few models with an adjustable stand too and thought I should have grabbed one of those.

I still think they could be on to something if they threw a whole bunch of those 5mm LED's in (like the Fusion 36) to get 200+ lumens and still have great runtime. Do these Fusion 36 modules need any additional heatsinking? In a maglite, do they heatsink to the tube of the Maglite too?

Garry

So you've got me thinking, since more is better maybe I should risk the ACE light. Before I melt my precious work light I thought I'd see what kind of temps the Ministar1 and TLE-6EX generate. I started by installing the Ministar in a 4D Mag with the head removed. Temp of the Ministar before installing was approximately 60 degrees F. Turned the light on for 20 minutes then off and quickly removed the bulb (didn't feel hot at all). The highest temp I could find on the module was 69F. I let the Mag sit for about 30 minutes, not that the Mag has any heatsink to stay warm but dinner was ready. Installed the TLE6 (starting temp also about 60F) and let it run 20 minutes. When I took it out it was obviously hot but not a problem to hold, highest temp was in the mid 130sF. Not to bad, I think tomorrow I'll try again running the light an hour or so, I'm also going to check the amperage at the tailcap on both bulbs.

I've only seen pictures of the Fusion 36 installed so I have no idea if they heat sink to the Mag body, I know the Malkoff drop-ins and to a lesser degree the TerraLux TLE-300 modules do.

I converted an 3 dollar walmart floating 6 volt flashlight to an XML with a Nanjg 105c driver. I set it on low tail standing during the 3 day power outage we had last week and the driver got so hot it melted the reflector. So don't use this driver for your conversion the voltage is to high for it.

Good to know!

Garry

http://kaidomain.com/product/details.S008846 This driver should work out great. Put an xml with a big hunk of aluminum and you should be ok. A way to conduct the heat to the outside of the lantern would be the best, but there should be room in there for a good amount of metal.

Hello,

I run an alternate energy class at the local Community College. The class consists of building models and devises to demo ideas, efficiency or methods of energy use. One of the projects consists of converting a 6 volt lantern flashlight into an LED flashlight. We first construct a current regulator and then modify the flashlight to accept the ~122 lumen XPG Cree LED. I have the LED mounted on a thermally trnsmisive heat sink carrier board. I presently have limited information about the project up on my site. The site is being redesigned so the link I am providing my change in the near future. In the class we drive the LED with ~.188 amps. This drops about 2.75 volts across the LED, thus a little more than ½ watt. http://www.angelfire.com/biz/petflicker/index_files/Page1552.htm

Good luck.