How powerful is my $9 homemade light ;)

OK ... I know this is silly, but while I was waiting to find the perfect, powerful, long throwing flashlight I made a crude light from some plumbing parts and a 50 Watt MR16 narrow flood bulb.
I even duct taped it to my motorcycle helmet to ride with some friends. Another guy had a 35 watt, MR 16 HID niterider light and mine seemed much stronger. (His was much "neater" though but $350).

Here's my silly question. I'm using a makita 3 amp hour, 18 volt lithium battery on the 12 volt, 50 watt bulb. This may sound strange (actually probably not cuz I'm sure you're all smarter than me ...) but with the 18 volt battery is seems more than 2X stronger than when it is running on 12 volts. Can anyone tell me why that is? In fact, I also have a 35 watt bulb and side by side the 35 watt bulb with the 18 volt battery is much stronger than the 50 watt bulb with a 12 volt battery ....

Here's some pics:

Overdriving a bulb means it makes more light. There's an equation that describes it that follows the 12th or 13th power. LuxLuthor would be a good one to explain it.

TorchBoy said:

Overdriving a bulb means it makes more light.

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At a greatly reduced bulb life. Put this in Incan section and you'll get more specific answers? Sometimes 2000h bulbs become 10h bulbs when they are overdriven just a few volts. You're increasing voltage %50, which is one great hot-wire. But maybe get a spare bulb ready b/c that one may not last very long (especially on bumpy rides?)
:welcome: nice entrance

rickypanecatyl said:

but with the 18 volt battery is seems more than 2X stronger than when it is running on 12 volts.

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if to your eyes, you say 2x, then in reality, it's 4x...

heck of allot you're overdriving that bulb.

Is that setup safe? Overdriving a bulb by increasing the voltage a good 50% is dangerous enough, but to put it on your head, and run it on a lithium ion battery makes it even more dangerous.

Hooked on Fenix said:

Is that setup safe? Overdriving a bulb by increasing the voltage a good 50% is dangerous enough, but to put it on your head, and run it on a lithium ion battery makes it even more dangerous.

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Motorcycle helmets should stop most flying glass and molten tungsten. Tool packs are designed for HEAVY drain and has protection circuits to suit.

Hooked on Fenix said:

Is that setup safe? Overdriving a bulb by increasing the voltage a good 50% is dangerous enough, but to put it on your head, and run it on a lithium ion battery makes it even more dangerous.

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There are certain things in this world a man does well to carry to extremes!!!!

What you've done, sir, is discover what we here call a superbulb. Defined by their capability to tolerate much too much power, these become incredibly efficient and incredibly powerful.

Please post box photos and model numbers?

Edit: that's probably pushing 100 watts, and operating at around 50 lumens/watt... that's in Torch territory.

Chrontius said:

Edit: that's probably ... operating at around 50 lumens/watt...

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Probably not. Let's not get carried away, here. :ironic:

As far as safety, it is on top of my helmet and I have eye protection.

I don't care if it blows the bulb as they are only a few bucks. I have had it on for a couple hours so far with0ut blowing out.

I try not to turn it on till I moving so that the air can cool it ... even so I do turn it off every 3 or 4 minutes or so as the rubber starts to melt. By far the most expensive part I wouldn't want to see break is the $70 or so battery.

I am really curious is anyone knows what the actuall wattage is on 12 volts 50 watt bulb with 18 volts of power ...

TorchBoy said:

LuxLuthor would be a good one to explain it.

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Send him a PM.

rickypanecatyl said:

Here's my silly question. I'm using a makita 3 amp hour, 18 volt lithium battery on the 12 volt, 50 watt bulb. This may sound strange (actually probably not cuz I'm sure you're all smarter than me ...) but with the 18 volt battery is seems more than 2X stronger than when it is running on 12 volts. Can anyone tell me why that is?

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Short answer: v=i/r

Long answer:
When you increase the voltage you will also get an increase in amperage so that 50% more voltage + more amps = more than 50% increase in wattage. On top of that incandescent bulbs become more efficient when they are over driven, this means that driving a 50W bulb at 100W will result in more than twice the light output.

So:
12V x 4.15A = 50W
18V x 5.56A = 100W
And running a 50W bulb at 100W will lead to maybe 3 x the light output, but it would turn a 2000 hour bulb into a 30 hour bulb (that is what happens to an Osram 64440 bulb when you run it at 18V anyway).

Be aware of the shorter bulb life and also the quicker drain on the battery and carry spare bulbs.

BTW
I have a 12V bulb that I am running on a regulated 20.2V - it is freakin' awesome! It is a 90W bulb, but running around 210W and producing about 4X as much light output (based on Lux Luthor's destructive tests of the same bulb).

A more durable housing for an mr16 bulb would be a piece of 1 1/2" copper pipe cap. You could put a switch on the back and epoxy a nut over a hole in the bottom to attach to a mount. You could get fancy and solder an overhead wing to help dissapate the heat. End up looking like the rocketeer with a gas leak.:duck: