making a an ammo can light and need help on the concept stage

This is my 2nd light of this style and I want to make my next one better.

My first one was a plastic project box a little smaller that a shoe box with a metal top. I mounted 2 35 watt flood automotive flood lights to it. It had a 7AH SLA with a built in charger. It has a handle and everything.

I am thinking about making a light out of an ammo can. The 50 cal, very popular size I see around a lot.

The idea was to have a 100w LED with heatsink and fan attacked to 8 18650 batteries. I know total flood that's what I'm going for, like my last one.

I'm open to all comments or any suggestions. Please fill free to chime in.

The main thing I'm having trouble understanding is how the LED heat sink and fan are mounted to each other then mounted to the surface you're mounting it on.

I was thinking about using this heatsink fan combo.
http://www.ebay.com/itm/30W-50w-100...966?pt=LH_DefaultDomain_0&hash=item3a9087767e

and this led
http://www.ebay.com/itm/100W-Cool-W...907?pt=LH_DefaultDomain_0&hash=item2ed05ff7d3

I don't know how or if this would even work. I'm confused as to how... or if they would even fit together.

Once again I'm asking for suggestions if you know have any better parts.

As far as a switch, batteries, and all the other stuff I think I got that pretty well under way. This is just my first LED build and am confused as to the LED part.

That is a Computer (CPU) heat sink. It has a flat plate on the bottom that is pressed against the high-power processor chip. The mounting hardware (Plastic & screws) is meant to stand up to use in a desktop, not a luggable case. It may not be strong enough - You can drill through the fins or bolt between them to mount the heatsink to the side of the box. The fan either has to circulate air from the room, or can just heat up the whole metal box (Moving air inside the box weighs less than using solid metal to get good thermal conductivity). A fan exposed to outside air is best for cooling, but is vulnerable to whatever else is in your air. Water, grit, dust, hair, etc.

The LED would be attached to the flat plate on the heatsink. Use thermal epoxy or screws, something SOLID. I suggest wiring a thermal snap switch in SERIES with the LED. This will not conduct power while above a given temperature. 80C is fairly common for hot water applications, although higher-temperature ones (120C) will let you run nearer the edge of the envelope. This will help to protect your electronics from heat.

An optic or something would shape the beam a bit, but if you just want pure flood, mount the heatsink so the LED is close to a window in the box.

I just wanna say that I think an ammo can light is a phenomenal idea.

Thanks tobrien!

I was thinking too if anyone had any parts they would suggest that would be nice too.

@ AnAppleSnail thanks for the info about the heat that will come in handy

Oh yea just for fun this is the first one I built.

It originally meant to be used in the flat position but then decided it worked better up right. That's why it only has lights on one side and the labels are side ways. The bolts are charging ports 12v in NOT 120! The handle it loose and needs spacers.. It still needs work I was just using spare parts to kind of test a concept. It seems very usable, even with a 7AH battery.

oh yea there 35 watt bulbs..

and it has a strip of LED's I robbed from an old LCD picture display. I don't have them hooked up yet though..

Cool Idea! I have a couple of those boxes...

Are you planning on mounting the LED inside the box, or outside like your first one? The box has about 350 sq. in. of surface area, so theoretically it should be enough to dissipate the 80W or so of heat from the LED, if you use the fan to disperse the heat effectively throughout the box.

100W from 8 cells of 18650 is quite a bit. I hope you aren't planning on running it for long. Even with the best cells available, you won't get better than an hour. I'd think about doubling up on the batteries, since you have so much room.

Here is a link to my ammo can light thread, although this one is a thrower.
https://www.candlepowerforums.com/threads/383227

The squared LED light setup from an exit sign that is very common might work if you are looking for something like that. They work on both 110v and from a low voltage battery. It would look cool around the edges.

@DIWdiver yes I started to think the same thing.. I'm thinking 16 would be better.. I thought they were expensive but I found some with charger that were pretty cheap. And the mounting is probably going to be the problem. I don't know how they are mounted and looking at a setup I found online with a fan/sink/ lens they are pretty big.. So I think I might opt to do it on the outside.. Do you know if the fans are a waste of do they really help cool that much better?

A fan properly used will improve the performance of a heatsink quite dramatically. They are a waste if not needed, but critical if needed.

To keep that LED cool without a fan you'd need a pretty big heatsink.