That correct. The driver can convert some voltage down, like 8.4V at the batteries -> 6V at the LED, but burns the excess voltage away as heat in the FET, which is also the reason the FET is placed on the ledboard.
LD-x4(HV) is linear constant current driver, linear means driver regulates output current by burning excess voltage into heat (via electronically variable resistor,which is mosfet in this case),so its output voltage can't be higher than input voltage; constant current means output is current regulated, driver doesn't care what output voltage would be, as long as LED voltage is lower than battery voltage, output current will be constant.
Plenty of people have made hot rod type lights with 4x26350 but if you really want to use XHP35 you may be best served to wait for a good boost driver so you have more battery options. (or go with one of the existing mediocre boost drivers that are out there)
No I meant 4x26500’s, for some reason I thought C’s were the same length as D’s cells just smaller diameter? I have several lights that run 3 cells (18650/32650) and now they run 4x26500’s and 4x18500 with the XHP35HI/HD’s in them, that’s why I stated possibly I wasn’t too sure of it.
I understand it would work, but I don’t think I’d be happy dealing with 4 cells for only 2000mAh.
But maybe xhp35 is more efficient to run than xhp50.2? Or does the drivers output current rating determine efficiency?
Not sure I’d consider this a “Hot Rod” by today’s standards, but I suppose it could be.
I could get the MTN-MAXlp HP, but this LD-x4(HV) seems to have much more going for it, almost like a “Dream Driver” ?
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Sorry if it’s been mentioned already but does the mosfet create additional heat at the mcpcb?
I would say go with 3Amp driver and XHP50.2, that light has no cooling fins and questionable switch current capability, everything above 3Amps would be too much for this host.