3s or 3p off of 6v

[videoman]

Got 3 XPG's R4 on 10mm round boards and have a choice to use buck or boost driver. The Shark buck 3A or the Blue Shark ( boost), The supply will be 4-AA alkalines or rechargeable 4-AA NiMh. I will be underdriving them at around 800ma. Which setup would be more efficient as far as battery run time ? Buck or Boost ?

 

[Gunner12]

I think buck would be more efficient, in this case, as long as the LED have similar Vf.