Some advice for a newbie please.

[diveuk]

Ok guys, I have been hanging around pestering you for a while now, I have finally got the inspiration to do a project but I am still an electrical retard, I can solder and put things together but am no good with the theoretical stuff so I need your help please.

I want to create an umbilical torch, I have the donor head,

http://www.ebay.com/itm/80M-Underwa...8840011?pt=US_Flashlights&hash=item20cf6adacb

I have a battery pack and cable, but what do I do now?

My donor head has 1 xml-t6 led which runs off of a 26650 battery, as i understand it xml's can only run @ around 3.5 - 4 volts, the battery pack that I intend to use is a 12v 4500mah pack, so can I use a driver to reduce my 12v to 4 volts? I have this driver laying around

http://www.ebay.com/itm/360472948472?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

can I just wire this between the battery pack and the existing circuit? Or would I be better off creating a new battery pack of some 26650 batteries in parallel?

If I go with the 26650 batteries how do I charge them?

 

[DIWdiver]

Yeah, you could use that driver, if you wanted to massively overdrive the XM-L. I've recently learned that some people have driven it that high, but I wouldn't recommend that driver unless you felt up to changing the current sense resistor to drop the max current.

This one would be a better fit, out of the box:
http://dx.com/p/6-18v-3000ma-3-mode-circuit-board-for-xm-lt60-emitters-57779

There are as many different charging methods as there are opinions on which is best. Do some searching on the forums, and you can learn a lot. It's been discussed ad nauseum elsewhere.