[twomanywh33ls]

i am building my own 12volt halogen headlight, and im confused on the topic of the battery. ive heard that a battery with 13 or 14 volts will produce more light but shorten the life of the battery. do i need all that power or will a few rechargable battery packs at radio shack work?

i dont have a lot of money to spend but id like to get a lot of light and life out of my system. i am also a little confused on how to connect the light to the battery any help would be appreciated thanks

 

[super-fast]

When you connect a 13 or 14V battery package you don't short the life of your batteries, but you short the life of your halogen bulb. It is calld "over volting". You get a lot more light, but you have less ridetime when your batteries have the same capacitiy and your bulb will not survive too long, after a few hondred hours it will be gone.

 

[dnlwthrn]

super-fast is right about the bulb life. But, if you're doing something similar to the Pond Scum setup, you can get replacement bulbs for $3-4, so its worth it. Easy answer on the battery packs: if you have RC car battery packs (7.2V subC size), you can get/make a y-cable that will allow you to run two of them together to make your pack 14.4V...

Check out the "Pond Scum" thread on an easy way to set up and wire a single 12V light...

 

[twomanywh33ls]

if i over volt my 12 volt light with a 14.4 volt battery how long will my run time be and is a 12 volt light going to be bright enough?

 

[womble]

"is a 12 volt light going to be bright enough?"

Well, it depends on the wattage of the halogen bulb and the terrain you're riding in. 10, 15 or 20 watts are the common options. A 20W 12V bult overvolted to 14.4V is very bright. Runtimes determined by the wattage of the bulb and the capacity (amp hours) of the batteries.

 

[thasingletrackmastah]

I've used a 12V 20W MR16 20 deg. halogeen for several years on 14.4V.
Here in Europe the Osram IRC series is the bulb of your choice.
The light was bright enough for serious off road use.
I used the above mentioned 7.2VRC batterypacks in series.

Powerconsumption was about 25W at 14.4V, thats about 1.75 A.
On a batterypack of 3500mAh you'll get 2 hours of ridingtime.
After that your in the dark.

Recently build a tripple led light, using Cree's XR-E P3.
I get about he same ligt, at less than half the powerconsumption, so the rideing time is more than doubled :thumbsup:

 

[scar]

thasingletrackmastah - Do you have any pictures of your triple Cree build up? I have been thinking about doing the same but don't know where to start.

 

[thasingletrackmastah]

Take a look.

 

[scar]

Excellent job. The electronics part is what is keeping me from jumping into the LED waters. I see you built your own drive circuit, very nice. I am thinking I want to try something like 3 Crees mounted on a 50mm circular PCB like this
http://www.cutter.com.au/proddetail.php?prod=cut651
And it looks like I can drive them at 1 amp. Now trying to decide on a suitable driver and optics that will all fit into my PondScum housing.

You mentioned that you are getting "about" the same light. So do they still not compare to an overvolted halogen?

Thank you very much for sharing the photos, it has me one step closer to jumping in.

 

[thasingletrackmastah]

I've not been able to compare.
The batteries of my halogen exploded during their last fast ( 25 min) charge...
They were not suitable for fast charging, but I did it anyway, got away with it for some time.
But the leds are equaly suitable for offroad riding in terms of light.
My overvolted halogen overshadowd a 50halogen spot in my livingroom, and so does the tripple Cree (800mA).
Mind that 3 Crees need some cooling.
The heat produced is not much, but it needs to be lead away from the emitter, to the outside world.
That is the main concern when building a led light.
Most DIY ledlampbuiders use aluminium profile and thermal 2 comp glue.