KD has a new 30W boost/buck driver for multiple Li-Ion, multiple XML. Boosts in 3xXML + 2xLiIon, bucks in 1xXML + 2xLiIon or 3xXML + 4xLiIon. Three modes, temperature sense, low voltage protection. Quite pricy for $15 but still looks like a good driver to have.
This would work well with a 12v source for three XM-Ls.
There are cheaper alternatives for 12v, as you don't need the boost circuit. The DRY driver from cnqualitygoods.com is five bucks, for example. Manafont has a $5.80 offering as well, even if their version is a bit bulky.
Dont want to derail the conversation too far away from flashlights but the DRY is DD so I figured it would pop given a car batterys amp potential. This one seems to be regulated with the 3 amps for 3-4 xml configuration and 5 amps for single XML
Actually, I'd assumed 3 xmls would still "only" pull 5A each if I used a DRY driver in turbo mode (direct drive) w/ my deep cycle 125AH lead acid battery, depending somewhat on the quality of wiring and connections...
Not saying I don't believe you, just that there's something I don't understand. I guess the deep cycle would have 0 voltage sag (even w/o being in a running vehicle w/ alternator). I know it doesn't have any trouble sustaining > 40 amps to my trolling motor:)
I checked this driver, with SST50 it goes 2.8A on led (3.8A tailcap) with one cell and 4A (2.4A tailcap) on 2 cells, driver blinks twice on 1 cell, so it would propably shut off after 3 minutes as mentioned in description. And guys, it is not protected to polarity reverse, smoked mine in 1 second trying to connect wrong way to battery pack... ;)
I have ordered one as first as they showed on ebay and wait for it :) Other case willbe my own project of Shadow JM07 Pro, which I want to make 3x XML with ledil cute optics. If no other way will be found, it will ba a biiig amc sandwich ;)