Modified P7 flashlight into 3" bike light

[EL34]

Howdy all.
Currenly I run two HID lights for off road mountain biking. I live in the mountains of western North Carolina.
I now run a helmet mount spotlight HID and a handle bar mount wide angle HID.
A few years back we ran halogen lights and they sucked once we saw how bright HID's were.
HID's are great, but looks like LED's are the future.
Commercial LED and battery combo's are $500 or more for the high end bike lights.

I purchased a couple model 18650 LED flashlights from deal extreme to experiment with
http://www.dealextreme.com/details.dx/sku.12325

I modified one into a 3 inch long bike light that I am going to mount to one of my Marwi handle bar mounts. I still have to machine that adapter.

The next thing is batteries. I have to run out and meet some buddies for a ride now, but I will be back this afternoon. I want to ask some questions here about batteries when I get back later.

I the mean time, have a look at my machined light project here and let me know what you think.
http://www.el34world.com/Misc/bike/BikesLights1.htm

Thanks, see ya later

 

[rayman]

Nice job with the lathe :thumbsup:.

But I think if you want to drive the P7 at 2800mA the heatsinkng will be very small. Maybe you could get a mount with which you could use the bike bar as an additional heatsink.

rayman

 

[EL34]

I just noticed I had two of the same photos on my web page and I fixed that.

I am going to machine a 6061 aluminum clamp/bracket that will let me connect the light to my existing handle bar mount. We only use the high setting on lights on the downhill and it's always winter when we use lights.
I am thinkning that my aluminum bracket can be made to help with heat sinking. The air is very cold on the decents. Hopefully the combo of cold air and my bracket will do the trick. On the slow uphills, we switch to low power settings and the heat is not an issue

Ok, on to batteries.

I build my own battery packs using Sanyo 4500ma 1.2v Ni-Mh batteries.
I typically need 2 to 3 hours run time and I do not like to drain my batteries all the way down and so I have extra mah on tap.

I have 2 really nice digital display chargers that do everything under the sun including just excercising the batteries during the summer months when they are not being used.
My HID's are 9.6v and 12v and so it takes a bunch of batteries in series to make a battery packs for those lights.
The LED being 3.6volts, I would have to use 3 NiMh in series and then put more of those in parallel to get 3.6volts and up the total mah.

I was wondering which way to go, build some more NiMh packs or get some of those 3.7v 2400mah li-ons from Deal extreme?

Any advantage to using the Utrafire batteries from DX and are they decent quality?
I got burned on some chinese Li-ons a few years ago and so I am being cautious.

Another question about that two setting flashlight I bought. I only tested it with some really old batteries I had laying around, and I only saw about 1 amp current drain. The NiMh batteries I used suck and are not long for this world, but I was wondering if the Hi-low electronics in the flashlight were holding back the total current flow? I know the low setting is of course, what about the High setting?

 

[EL34]

Ooops, double post

 

[tr0ll]

hi - i'm considering getting a mte ssc p7 and modifying it - so it can use external battery.

i really do not care how much weight the battery weighs (i use a backpack anyway). i am currently looking at a small mc-battery (6v) - which is 8cm x 7cm x 10cm and delivers 2A,

what runtimes can i get on this with full throttle ?

 

[EL34]

The P7 LED is a 3.7 voltage device. The 18650 lithium is a 3.7 volt battery and a good choice

The total mah of the battery pack determines run time and the quality of the batteries themselves also determine run time. I have seen times listed with 1-lithium at around an hour, probably more like 40 minutes of good light, (just guessing) and then not as bright. Not good to run the batteries all the way down.

I am going to build a 4 - lithium battery pack and do some testing.
It will be a couple weeks before the batteries are here.
I'll post the info on my web page when I run a test or two.
http://www.el34world.com/Misc/bike/BikesLights1.htm

Also, I am posting more on the MTBR bike light forum than here.
That thread is here.
http://forums.mtbr.com/showthread.php?t=483036