Building my first light, need help

Hello everyone, i am very new to this but i'm not afraid of a soldering iron and a little work. I'm looking to build the brightest headlamp and accompanying handlebar mounted light i can for use while mountain biking. I have a few lithium polymer batteries from RC lying around, most are 11.1v 2100mah capacity and i would like to use them for power, but i'm not sure if thats going to be possible? I was planning to use the parts and instructions found here http://www.instructables.com/id/EJEQALWNQ9EUBYRDXF/ because i'm obviously clueless but my biggest concern is that the list is outdated. Any suggestions on alterations to that list or even help starting a new one would be fantastic!

:welcome:


Somebody who knows will get here soon.......

luxeon stars?
yea, those are a bit outdated.

as a standard, maybe a CREE Q5, or R2.

it's going to be hard to power the LEDs with those battery packs.

maybe you should consider having preassembled lights, maybe from dealextreme? they're pretty cheap.

of course,welcome!

Or...


Have a good look around the forums here and search for some natty, catty awesome builds....!

Try the CPFMP aswell.....!
Do not be afraid to ask anymore Q`s my friend....!

Thank you both for the replies i appreciate it. I'm definitely not going to get hung up on using the lipo packs for power, whatever is going to be the easiest to implement is what i would go with. My goal is to build something equivalent or better than this: http://nashbar.com/profile.cfm?cate...and=&sku=10039&storetype=&estoreid=&pagename=

3-4 Cree XR-E Q5s or R2s or a single Seoul P7 or Cree MC-E should equal the output of the HID light. Check this sub forum.

How much are you willing to spend on this build?

Thanks Gunner, i'm willing to spend up to the cost of the light i linked to ~$400 , but if i can achieve similar results for less that would be great because i'm going to be needing 4 lights total.

Those li-poly batteries are great for bike lights. High power, low weight. One of them will run 3 XR-Es for about 2 hours.

If you want cheapest, string 4 of these drop-ins together in 2s2p with the right enclosure for decent heatsinking and heat transfer from the drop-ins(when riding the moving air should help cool the light). That should be less then $100 total.

If you want more DIY(and easier to garantee good heat transfer from LED to heatsink), you can try 4 Cree XR-E LEDs, Q5 or R2, with the right optics/reflectors, and the right driver. Total should be under $150.

Or a Seoul P7 or Cree MC-E with a reflector/optic instead of the 4 Cree XR-Es.

Thanks, can you recommend a site which carry's the drivers so i can look into that more? Also, i'm going to need some type of low-voltage cutoff is that built into the drivers or a separate unit?

Most(almost all) drivers lack a low voltage cut off for Lithium rechargeable batteries, you will need a separate unit.

As for drivers, there are many sites, Dealextreme and Kaidomain have some cheaper ones(look at the reviews). The sandwich Shoppie also has quite a few. There are also many electronics shops online that should have them.

For your task, a boost circuit(I often switch between driver and circuit, even though they are different) should work to boost the 11.1v to around 14.8 needed to run 4 LEDs in series(or the MC-E wired in series). Or a good buck driver if you are using a Seoul P7.