Mod project with beamshots

My first attempt at home-modding a flashlight may be different than most, but I like to try off-the-wall things, so please bear with me. The light I want to mod is a DeWalt 18V work light, shown below.



The 18V rechargeable battery powers tools like drills and saws, so it should handle a decent amount of amp-draw (I searched Google and could not find any specs on this battery, other than being 18V).

The light already comes with a metal reflector, so I think all I really need to deal with the heat of a better bulb is a glass lens and probably an internal heat sink. Depending on the amp-draw of the bulb, I may need to upgrade the switch too (not sure yet).

For those curious, I am not interested in any LED options at this point. Yes, I saw the thread with the 18V LED monster light that is very, very bright. For this project I want to stay with incan.

So here is where I am at and a series of questions I have:

I haven't had any luck finding a good 18V bulb. I searched a bunch, maybe I am searching in the wrong places? Anyone have a link?

I did find a Halogen bulb at Fry's Electronics that is 12V and 50W. Might be a good (and cheap at $2.99) starting point. My first question with this bulb is can it be overdriven to 18V at all, and if so, will the life-span be vastly shorter? I took a regular automotive 12V brake light bulb and drove it on 18V, it was really bright for about 10 seconds, then .

If I can't overdrive it to 18V, can I just put an inline resistor to bring the voltage down to 12-13V? I would think that would work as long as the resistor can handle the 4.2amps.

This halogen bulb is the bi-pin type, with a 6.35mm spread. Does anyone know of a bi-pin bulb holder that is available? I looked at Fry's and at Radio Shack with no luck. Any links? I'm also willing to cannibolize something if anyone knows what kind of light originally used these types of bulbs.

Anyone know of any BETTER bulbs that will work on 18V and not cost a fortune? Don't have to be bi-pin, in fact I would prefer it if they were not bi-pin.

Thanks for any help you can provide.

Re: Planning my first Mod, have some questions

So I tested the 12V 50W bulb on the 18V battery for about half a second. It got very bright very quick! As I knew it would. But I'm afraid to try longer tests since I only bought one bulb (I should have bought 5 of them so I could play around).

Re: Planning my first Mod, have some questions

I did one more test. I put the 12V 50W bulb in the DeWalt reflector, held in with aligator clips, not very scientific, but I got a pic at least. I took it in the bathroom and powered it off the 18V battery. It was brighter than the normal bathroom light. And an incredible flood pattern. The pic below was at a distance of about 4 feet, yet notice the wide spill and overall white light almost everywhere (again, the bulb was rigged in the reflector, not the best way to test).

I may be on to something here...

Re: Planning my first Mod, have some questions

Edit: oops, I completely forgot to say that this looks like an interesting and really cool mod. Keep us posted about it.

KingGlamis said:

I did find a Halogen bulb at Fry's Electronics that is 12V and 50W. Might be a good (and cheap at $2.99) starting point. My first question with this bulb is can it be overdriven to 18V at all, and if so, will the life-span be vastly shorter? I took a regular automotive 12V brake light bulb and drove it on 18V, it was really bright for about 10 seconds, then .

Click to expand...

It's fun to do that occasionally, isn't it? A 12V bulb should be ok if it's rated for 2000 (or more) hours. The bulb life rerating formula, if I'm not mistaken, is: (specified voltage / applied voltage)^12 * bulb life. So running a 2000 hour 12 V bulb at 18 V would result in 15 or so hours. Probably won't instaflash.

KingGlamis said:

If I can't overdrive it to 18V, can I just put an inline resistor to bring the voltage down to 12-13V? I would think that would work as long as the resistor can handle the 4.2amps.

Click to expand...

I wouldn't do that. The resistor will waste an awful lot of power and heat things up in the process.

KingGlamis said:

This halogen bulb is the bi-pin type, with a 6.35mm spread. Does anyone know of a bi-pin bulb holder that is available? I looked at Fry's and at Radio Shack with no luck. Any links?

Click to expand...

You can get ceramic bi-pin sockets from electronics stores, but they are not drop-ins, so you'd have to figure out how to mount it. They look like this:
http://www.vekoy.com/product_info.php?cPath=68_441_1400&products_id=11654

Re: Planning my first Mod, have some questions

Thanks for the advice. I'm off to work but I'll be back with a tinker update tonight (I may end up with a 75W bulb by tonight).

Re: Planning my first Mod, have some questions

I'm thinking this 18V DeWalt battery has potential! This is a shot of the 18V battery powering a 12V 100W bulb in a spot reflector/lens at a distance of about 20 feet. Damn near melted the wall. I may have to go out front and test the throw (just not sure my cheapy camera can get a pic of long throw).

Re: Planning my first Mod, have some questions

OOPS! I put the 18V battery pack I was using back on the charger and took a fresh one off of the charger to do the outside throw test. Instaflash! One bulb down the drain.

More testing/research will be needed obviously.

Re: Planning my first Mod, have some questions

Another test tonight. This is a 75W 12V halogen with a 1.75" semi-flood reflector running on 18V. Not to shabby if you ask me. I'll get this modding figured out.





Sorry it's blurry but my camera isn't very good at night. Lights up the house across the street pretty well.

Here are the results of my test out front. This was also with the 75W 12V Halogen on 18V.

First pic, my truck headlights on HIGH beam.



And now my project light from the same spot. If I get these results from cheap bulbs I can't wait to get my hands on some real bulbs.



And finally, the same light shining on some really tall palm trees by my house.



Thoughts anyone? Is my project too odd for anyone to care?

Wow, if it can beat the high beams of a car, it's plenty bright! Very nice!

What's the mAh rating of that batterypack you are using? What kind of runtime are you expecting for it?

Valolammas said:

Wow, if it can beat the high beams of a car, it's plenty bright! Very nice!

What's the mAh rating of that batterypack you are using? What kind of runtime are you expecting for it?

Click to expand...

From what I read in another thread on here, the battery is rated somewhere between 1500mAh and 2400mAh. I haven't been able to determine what it really is. But this same battery runs the DeWalt drills and saws and such so it packs a punch. I have no idea what to expect for runtimes, but it really doesn't matter because I'm doing this for fun and I have four of the batteries, so I'll always have a fresh one ready.

As a comparison to last night's pics, here are two shots from the same range using my cheapo "1.5 Million Candlepower" spotlight. Notice it has zero spill at all, and doesn't even light up the distance near as well.

Just for fun I decided to compare three of my other lights.

This first one is a Mag 4D with Mag LED drop-in. Does OK with throw, but not even close to my experimental light.



This next one is my stock DeWalt 18V work light. It's built more for flood. Sorry for the blurry pic.



And... just to see what would happen, my EDC Streamlight Twin Task 2-L. At least it lit up the street sign, if nothing else.

Cool project, KG. With either the 100W focused, or the 75W flood, that thing is really bright!

:thumbsup: