# Overdriving a 12v 50W Halogen at 18v???



## KingGlamis (Jul 8, 2007)

Anyone ever overdriven a 12v Halogen to 18v? I did today, up to 10 seconds at a time, and it was very bright. But I'm concerned about bulb-life. Anyone know what I should expect if I try to run a 12V, 50W Halogen off of 18V full-time?


----------



## mdocod (Jul 9, 2007)

actually many of them can handle up to around 20V+ before they pop, it all depends on how many hours life they are rated for at 12V... most 2000 hour lamps will tolerate up to around 18.5V for around 10 hours, a 4000 hour bulb will tolerate about 19V for about 10 hours, and a 6000 hour bulb, will tolerate about 19.5V for about 10 hours. these are approximations but true...

another interesting thing, is that as you drive the lamp harder you gain higher color temperature (approaching 3500K when you really push em hard). You also gain efficiency as you drive harder. Many of these halogens will achieve 35+ lumen/watt when driven that hard. 

to answer your question more wholely, many people are running MR-16 style lamps that contain those 12V halogens, with ~14-16+ NIMH cells, with great results.

[edit in]
BTW... at 18V, your bulb becomes a 93W bulb.


----------



## LuxLuthor (Jul 9, 2007)

KingGlamis said:


> Anyone ever overdriven a 12v Halogen to 18v? I did today, up to 10 seconds at a time, and it was very bright. But I'm concerned about bulb-life. Anyone know what I should expect if I try to run a 12V, 50W Halogen off of 18V full-time?



Which bulb? Always easier to give more direct feedback if we know which one.


----------



## FILIPPO (Jul 9, 2007)

I did it few month ago but I get a really short runtime and after few minutes the light was yellow...(I overdriven it with some energizer)
you must use some high current batts. for the best output


----------



## Learjet (Jul 9, 2007)

What about a Philips 7023?


----------



## aerosimon (Jul 10, 2007)

My favourites are the Osram Decostar 35 IRC and 50 IRC getting the 35 up to an on 60 and safe is great. the beam patter is nice too, unlike the 20W version which is more bluish and of different pattern altogether.. I recently tried the Phillips Halostar (i think, ill check packet another time) and it has a convex lens built into the front cover. It claims an 8 degree beam unlike the osrams at 10 deg. Iv tried it and true to claim it is much narrower spotwise at range, HOWEVER I cant see any better with it, so i dont know whether we are actually getting any more lux on the target or not. By eye Iv chosen to stick with the Osram, and it fits mags because its flat, but it really does open the field better with no perceivable cost to the hotspot intensity.. Shame really, i wanted more cp

I have overdriven the 50 severely also, because i wasnt going to use it as a project at the moment, so it took up to 105Watts, which by the 'theory' gives me 7000lumens (although darn, the theory only works within X% of the initial design drive voltage But its damn hot, thats for sure 

7023, ill look it up before commenting..


----------



## KingGlamis (Jul 11, 2007)

LuxLuthor said:


> Which bulb? Always easier to give more direct feedback if we know which one.


 
The package says:
Manufactured for Black Point Products, Point Richmond, CA.
The part number is MB-JC-50-T4.
The specs say 50W, 2000 hours, 12V, GY6.35, Bi-pin base.
It's a halogen.


----------



## aerosimon (Jul 11, 2007)

What is your intended use, and what are you trying to achieve. Are you using this for vehicle? and wanting a race distance out of it or something. Is all you are after the exact lifespan that specific bulb? If so, a test may be the only way to be more precise than what mdocod mentioned above, apart from rerating in the formula for exactly the voltage seen at the pins in your system. And then its still comes with no garauntee. 

Good luck


----------



## KingGlamis (Jul 11, 2007)

aerosimon said:


> What is your intended use, and what are you trying to achieve. Are you using this for vehicle? and wanting a race distance out of it or something. Is all you are after the exact lifespan that specific bulb? If so, a test may be the only way to be more precise than what mdocod mentioned above, apart from rerating in the formula for exactly the voltage seen at the pins in your system. And then its still comes with no garauntee.
> 
> Good luck


 
I'm looking to mod my DeWalt work lights (there is a thread about it in the home/mod section). And since the 12V Halogen bulbs are cheap, I thought I would try them. The pic below is a different bulb, a 12V 100W with a larger spot reflector, run on the 18V DeWalt battery. Distance about 20 feet. It worked great on a partially discharged battery, but I instaflashed two bulbs on a fully charged battery.


----------



## mdocod (Jul 12, 2007)

A fully charged dewalt 18V pack is actually likely to be higher than 18V, especially if it's a NICD pack. fresh off the charger, it could be as high as 23V with no load, and deliver well over 20V, which would very likely pop a 2000 hour 12V lamp.


----------



## KingGlamis (Jul 12, 2007)

mdocod said:


> A fully charged dewalt 18V pack is actually likely to be higher than 18V, especially if it's a NICD pack. fresh off the charger, it could be as high as 23V with no load, and deliver well over 20V, which would very likely pop a 2000 hour 12V lamp.


 
I'm sure you're probably right, which is why I'm looking for 18V bulbs. Just haven't had much luck finding them.


----------



## mdocod (Jul 12, 2007)

find a 12V rated for more hours and you should be ok... there's some longlife high pressure xenon lamps sold online for about $4-8 each at various place (like 1000bulbs.com).. they are "12V 10,000 hour" bulbs, and should survive the overdrive of that battery pretty well.


----------

