help for 3x p7 bike light

[dme25]

Hi everyone really in need of desparate help in putting together a bike light for all night Mountain ride. Have been trying to get help for a few months but this electronics stuff is messing with my head, its like living in a foriegn country not knowing the language Want to wire up 3 cree p7's together, think they need to be in series? what wire, resistor, batteries do i need. Also i know these things need a good heat sink, would really appreciate if someone could give me some kind of list to order, a kind of dummies guide. Thanks for any help Dave

 

[vtunderground]

I have some experience with building lights, but zero experience with the Cree P7. That being said...

What would you like to use for the battery pack? 4xAA? 8xAA? A custom Li-ion or NiMH battery pack? Your choice of batteries affects what LEDs and drivers you can use.

How bright do you REALLY want/need it to be?

How many light levels do you want it to have? Just one? A dozen? Infinite?

How long do you want the light to last before you need to replace/recharge the batteries? This is very important... 1000 lumens are useless if the batteries die 2 hours into a 4 hour night ride (or even 2 hours into a 2 1/2 hour night ride).

 

[dme25]

Hi Thanks so much for your willingness to advise, the p7's are rated at 900l each, so i would like to have about 4 hours battery life and want to invest in something good. Was thinking of housing these in 3 separate Aluminium torch heads that i will modify, but would need a good heat sink. Sorry for being a bit vague regarding the parts its just that its really a first build for me. So am totally open to any suggestion. I need them to do a black out bike trial in the middle of the night. i can source the spec for the p7's but don't know the first thing about what wire, batteries, power supply to get.
thanks again
Dave

 

[download]

For the electronic, check this out, will give you some hints.

http://www.candlepowerforums.com/vb/showthread.php?t=201392

 

[dme25]

Thanks stuff is slowly sinking in, can you advise on a battery for 4hrs constant use
Thanks
Dave

 

[Mettee]

For four hours I would think you would need a 8000ma pack. A lion pack or a lipo pack would be good. It may not run on high the entire 4 hours but if you have seen the output a triple P7 light puts out you will know that a medium level is still a LOT of light.

Something like this-
http://www.batteryspace.com/highpowerpolymerbattery111v8ah40arate88whwopcbforrcracing.aspx

or this for even more run time-
http://www.batteryspace.com/highpow...111v10ah70adischargerate111whwopcbfordiy.aspx

Although they are not cheap...

And I have used Netkidz amc driver solution and it works very well.

EDIT: saw this battery charger combo, you would have a spare battery to take just in case and it comes with a charger.
http://www.batteryspace.com/highpow...dischargerate88whwopcbintelligentcharger.aspx

 

[dme25]

Mette your advice is really appreciated thanks so much will let you all know eventually how this works out, thanks again.
Dave