Hiya G.B, I'm fairly interested in the progress of this, as it seems your main mission is to up the wattage output (brighter lights)with minimal current draw...but (maybe as so the other comments) I can't see that a higher voltage output will be any advantage...given the current draw to run it...?
I'm running a halogen 35/35 in a new Hella H4 (motorcycle) reflector and it's ok in ambient town lighting- I think... but I need to check (hand in front of) occasionally to see if it's working
...I'm thinking your 45/45 would be an improvement if on 6V, but being on the 12v setup...
..
I'm inclined to think as MF says
Even if the box is 85% efficient (which I very much doubt) why not increase the 6v headlamp bulb by the other 15% for the same power usage?
I'm thinking to do that, but will have to wait until November 'till the supplier gets back from his GB/Euro holiday...
With my limited knowledge of electrics, My system seems to provide a fairly constant ~7.2 volts at anything past idle, so if I was to go to a 50/65W, the genny would be working almost full capacity, but if it's there it needs to earn its keep
...I'd forget about the 400W of that unit though..that's a bit(lot) dreamy, as you're still governed by your battery capacity, and the Genny/Dynamo ability to keep the amps up...
Watts is Watts- I have a 50/65W on the (12V) Guttzi for around town, and it's ok but have a 90/100W for out of town and it's great but challenges the system in town (as per my blurb at the bottom), currently running through a Narva H4, but the Hella H4 seems to have a better spread pattern.
I also have a Lucas-'TVS'(Wasell
) 700 series "Foreign Headlamp" that I'll compare, maybe tomorrow....have wrong connectors!