Can I drive two Nichia GS with two AA NiMH?

[Cemoi]

As far as I understand the Nichia GS need a least 3.2V to work.
Two AA NiMH in series = about 2.4V.
How should I connect the LEDs (parallel or series) and which boost driver should I use to get the specified 20 mA current in the LEDs?

 

[Lynx_Arc]

Actually freshly charged nimh at about 1.4v each would be 2.8v and would drive the nichias in parallel but not at full output perhaps 10-12ma. As for the boost circuit to use part of that depends on where you plan to put this setup as there are various boost circuits some that would fit in a flashlight others that would fit in other spots. As I am clueless where you are in the world I am unsure what vendors to recommend.

 

[Cemoi]

Actually freshly charged nimh at about 1.4v each would be 2.8v

I'd like them to be still bright even when the NiMH individual voltage is down to 1.1V (i.e. not fully discharged). A regulated current would be appreciated.

As for the boost circuit to use part of that depends on where you plan to put this setup

In a bike headlight, with very little room available hence the smaller the better.

As I am clueless where you are in the world I am unsure what vendors to recommend.

In Europe, but ordering from anywhere in the world should be OK if the shipping charges are reasonable.