If you prefer the 3535 led then use a xp-l2 they have a low vf. Cree XP-L2 V5 5000K LED - Bare
TA’s test from xp-l2. XP-L2 V5 Output & Death test by Texas_Ace Over 2200 lumens! Still worked after 15 Amps!
Looks like it needs about 3.35v or so at 4.5 amps.
There is also a chance the vf could be a little lower or a little higher. Vf lottery 
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