you probably could, just need to check with an ammeter.
most of the high powered LEDs can be seriesed to a 12 V source, then depending on the battery state of charge, will vary (quite a bit) in output.
which works darn great, got juice you get light, if you didnt get enough charge, you still get light, less of course, but then it is using less total power, so you can continue like that.
this method is much superior (IMO) to fully regulating the thing, and draining your battery to nothing, when there is little in your battery to begin with.
(specially when lead acid doesnt like deep discharge)
so on them cloudy days, you get dimmer night, and sunny days you get brighter nights, and when you dont get sun for a few days, you still have SOME kinda light.
now i will also note that if you put motion sencors and light sencors on they would save like 98% of power TOO, because if its only on when your THERE, and the sun is off, then your gonna save more power than anything.
the length of wire from your battery will be resistance, when you add in more LEDs it will be more voltage drop, because your drawing more amps.
this all would go very badly:
1) if the VF is way to low low on your high powered leds, which it really isnt THAT much different at 3W than a luxeon.
2) when your battery is juiced up good, or charging AT the time the light goes on. then you could be looking at as much as 15V from the battery. (note it could get to 16v max, if you had little storage, and lots of charge, or no controller stuff).
so your "Range" is minimum of 10.5, and a maximum of about 14.5-15 . that is a pretty wide range, oh my 4 whole volts
but that is also spread out amongst 4 whole leds
. and led that will Squeak out a bit of light at 3.3, and be blowing smoke out itself at 4.3 .
so i would string it up WITH the wire your using, charge the battery fully, and put an AMMETER in. only testing reality is going to prove reality, then add any resistance to make it run at SPEC on the Highest charge level. when the VF changes over time, it will overdrive it a bit.
so mabey you COULD max at 1000ma, but if you spec it now at 700 for max, then when the Vf goes different, it will hit 1000max for a while.
i am saying its a GREAT idea, even if it doesnt make good math or science, it does make good "self reguation" based on ability of the storage and its charge.
are YOU willing to adapt to the battery ? or do you want FULL power always when ever it turns on, and eventually a drained battery?
the whole single volt change is a LOT of change, but i like it.
what do you have to lose? you could test it.
for my stupid method, have an ammeter, test your MAXES, with the WIRE, and any switch and sencors. set it to SPEC on your MAXes.
other wise there is 101 other methods:
3 to a string, and a resister, would give you much more voltage change room.
3 to a string and a 20$ buck thing, would give you perfect continuous light of the exact same value reguardless of how much battery storage you have left.
so they call it unregulated ;-) but my battery calls it Self-regulated
when we use this method, we replace a bunch of 20$ curcuits, with just MORE leds, because leds are more efficient when run lower, and will run longer in years when run lower, and because curcuit stuff complexes stuff , it should run forever like that.
and so far it has.
so if you gonna need ALL 12W of led power, everytime you turn it on, then REGULATE it.
otherwise TEST the "self regulation" method with a simple ammeter, your wire and switches, and the battery fully charged , or even charging AT the time. if the power is to high, shove an 4 Ohm of resistance in.
if you realise you dont like self regulating light, and its to dim to often, and you need to many leds, then have some way to restring it with 3x , and stuff a regulator in between.
and dont forget where the MATH thing is if you need it
http://www.luxeonstar.com/resistor-calculator.php
